bluuebunny/crossref_metadata_2025 huggingface dataset:
Staying English in Dutch Suriname (1667–1687)
Authors: Selwood Jacob
Published: January 2023

This chapter examines how English colonists preserved their status in the period between the Dutch conquest and the Glorious Revolution, using the example of the Clifford family and the wider colonial population. It identifies who sought to maintain English subjecthood, who abandoned it, and whose status was contested by the English and Dutch authorities. The chapter begins by examining how the colony's English governors sought to protect English inhabitants through the framing of the 1667 Articles of Capitulation, which defined the rights of English subjects under Dutch rule. It then turns to the evacuation of most of the English colonists in 1675, showing who continued to claim English subjecthood and who ultimately shed it. The Clifford family, along with most of the other English colonists, left the colony for Jamaica. The chapter closely follows the Clifford family on its return to Suriname after 1675 and traces Jeronimy Clifford's attempts to secure his status within a territory that was now almost devoid of English subjects.
Colonial Subjecthood in England and the Netherlands (1696–1737)
Authors: Selwood Jacob
Published: January 2023

This chapter traces Jeronimy Clifford's fight for restitution as he descended into poverty and, quite possibly, madness. From his arrival in England in 1696 until his death in 1737, Clifford sought compensation for his suffering and the right to remove his property—including its enslaved workers—from Suriname. As he did so the estate itself fell into the hands of others. The chapter explores how he deployed his subjecthood when engaging with the English Crown and its British successor, with parliament, and with the Dutch authorities. It pays particular attention to the ways in which he tried to bolster his subject status in order to convince agents of the Crown to act on his behalf and how the Crown and Dutch authorities responded to those efforts. Clifford advanced his claim by citing seventeenth-century Anglo-Dutch treaties, and by evoking his birth within England, his marriage, and his own patterns of migration. Despite having used his status as a subject to convince the Crown to intercede with the Dutch, his efforts had resulted in failure.
Introduction
Authors: Gibbons Rebecca Davis
Published: January 2023

This chapter introduces the nuclear nonproliferation regime. It elaborates on the 1970 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), wherein all member states except the five declared nuclear powers agreed not to develop nuclear weapons in exchange for access to peaceful nuclear technology and the promise of eventual disarmament. States adhere to the nuclear non-proliferation regime after the US government's decades of efforts to prevent the emergence of more additional nuclear weapon states. The chapter explains how the US foreign affairs bureaucracy begins to employ several low-cost diplomatic tools when a non-proliferation agreement has been enacted. Moreover, hegemonic stability theory was primarily developed to elaborate on the patterns in a global economy. The chapter also highlights the damaging impact of nuclear weapons which ranged between decimating entire cities and millions of people.
From Rural Dispossession to Precarious Urbanization
Authors: Campbell Stephen
Published: January 2023

This chapter explores the oral histories of Yadana's residents from their migration to their settlement. It explains a relational dynamic wherein the dependence of Yangon's high-octane urban capitalism on processes of rural dispossession and government neglect. Moreover, market compulsions intensified under postsocialist economic restructuring in Myanmar. The chapter looks into the narratives of residents affected by debt-driven migration due to locust outbreaks, the devastation of Cyclone Nargis, and agricultural wage laborers. The aftermath of Cyclone Nargis ultimately triggered the collapse of rural livelihoods and mass urban migration to industrial zones, where factories in the zone proliferated and sought young, low-wage employees. The chapter also provides an overview of the broader demographics of the settlements' inhabitants.
Educational Class Struggle
Authors: Koo Hagen
Published: January 2023

This chapter highlights the significance of education in Korean society and its corresponding educational class struggles. It references the Cho family scandal and President Park Geun-Hye's subsequent impeachment to emphasize the Korean society's intense reactions to the unfair advantages of people of power and wealth. Korea's education zeal stems from a strong egalitarian orientation on social status and a strong desire for upward social mobility instead of just aspiration. Moreover, neoliberal ideologies influenced significant changes within the Korean educational system. The chapter covers the growing class inequality in Korea that resulted in the intensification of educational competition and the abnormal growth of the private education market. It also covers the emergence of Gangnam moms who firmly believe education is the only channel to success and become their children's education managers.
In Pursuit of Global Education
Authors: Koo Hagen
Published: January 2023

This chapter explicates how globalization influenced the way affluent middle-class families adapted to the globalized education market. It looks into the phenomenon of wild geese (kirogi) families found in New Zealand, which had been the product of migration as women and children go overseas for the sake of pursuing education after being disappointed with the rigid Korean educational system. The chapter also considers the research into kirogi families, which reveal a commitment to Confucianism's core cultural values. Studying abroad remains popular among Koreans since it provides a convenient though highly costly means for well-to-do families to avoid their children's failure in the educational competition of their home country. The chapter explores cosmopolitanism in Korea which is commonly associated with extensive overseas travel and educational experiences.
Relationship between fruit phenotypes and domestication in hexaploid populations of biribá (Annona mucosa) in Brazilian Amazonia
Authors: Serbin Giulia Melilli , Pinangé Diego Sotero de Barros , Machado Raquel Moura , Vasconcelos Santelmo , Amorim Bruno Sampaio , Clement Charles Roland
Published: January 2023

Background

Biribá (Annona mucosa Jacq.) is a fruit tree domesticated in Amazonia and has polyploid populations. The species presents ample phenotypic variation in fruit characteristics, including weight (100–4,000 g) and differences in carpel protrusions. Two cytotypes are recorded in the literature (2n = 28, 42) and genome size records are divergent (2C = 4.77, 5.42 and 6.00 pg). To decipher the role of polyploidy in the domestication of A. mucosa, we examined the relationships among phenotypic variation, chromosome number and genome size, and which came first, polyploidization or domestication.

Methodology

We performed chromosome counts of A. mucosa from central and western Brazilian Amazonia, and estimated genome size by flow cytometry. We performed phylogenetic reconstruction with publicly available data using a Bayesian framework, time divergence analysis and reconstructed the ancestral chromosome number for the genus Annona and for A. mucosa.

Results

We observed that variation in fruit phenotypes is not associated with variation in chromosome number and genome size. The most recent common ancestor of A. mucosa is inferred to be polyploid and diverged before domestication.

Conclusions

We conclude that, when domesticated, A. mucosa was already polyploid and we suggest that human selection is the main evolutionary force behind fruit size and fruit morphological variation in Annona mucosa.
Effects of prohexadione calcium spraying during the booting stage on panicle traits, yield, and related physiological characteristics of rice under salt stress
Authors: Huang XiXin , Zheng Dianfeng , Feng Naijie , Huang Anqi , Zhang Rongjun , Meng Fengyan , Jie Yin , Mu Baomin , Mu Dewei , Zhou Hang
Published: January 2023

Prohexadione calcium (Pro-Ca), as a growth retardant, can effectively alleviate the damage of salt stress to plants. In order to explore the effects of NaCl stress on the physiological characteristics and panicle traits of rice plants as well as the alleviating effect of Pro-Ca at the booting stage, we performed pot experiments on two rice cultivars: conventional rice ‘Huanghuazhan’ and hybrid rice ‘Xiangliangyou900’. Rice plants were treated with 0.3% NaCl 48 hours after Pro-Ca (100 mg L−1) treatment to study the effects of Pro-Ca on the physiological characteristics of the leaves and panicles, as well as the panicle and yield traits of rice under salt stress. Our analysis indicated that NaCl treatment inhibited the morphological growth parameters and photosynthetic efficiency, destroyed the antioxidant defense systems of leaves and panicles, increased soluble protein and proline in both rice cultivars. Foliar application of Pro-Ca significantly increased the leaf area, uppermost internode length, panicle length, panicle weight, number of primary branches, number of grains per panicle, seed setting rate and yield under salt stress. Pro-Ca application significantly affected chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and apparent mesophyll conductance (AMC) in NaCl-treated rice cultivars compared with NaCl treatment alone. Moreover, Pro-Ca also increased ascorbic acid (AsA) content, enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity, and further increased the accumulation of soluble protein and proline in leaves and panicles. These results illustrated that foliar application of Pro-Ca at the booting stage could alleviate the damage caused by NaCl stress by regulating the physiological and metabolic processes of rice plants, thereby enhancing the stress resistance of the plants, increasing total rice yield in salt stress conditions.
Application of Agar-agar as Food Additives
Authors: Junianto . , Ashila Yasyfa , Rahmatunnisa Shafira , F Ghefira Zahra
Published: January 2023

This review article aims to study the types of seaweed that can be processed into agar, agar extraction methods, characteristic of agar, and application of agar as a food additive. Based on articles and other literature reviews, it can be concluded that: 1) The types of seaweed that can be extracted into agar-agar are Gracilaria sp., Gelidium sp., and Gelidiella sp. 2) Extraction of agar from seaweed can be done using the methods of Yolanda and Agustono [1], Wicaksono et al. [2] and Shantika et al. [3]. 3) The characteristic of agar can be reviewed from particle size, moisture content, ash content, heavy metals, pH, solubility, turbidity, gel strength, and viscosity. 4) Agar-agar as a food additive had been applied to analog rice, jelly drink, and edible film making.
Privet pollen (Ligustrum sp.) as potential cause of pollinosis in the city of Cordoba, south‐west Spain
Authors: Cariñanos P. , Alcázar P. , Galán C. , Domínguez E.
Published: July 2002

Background: Privet pollen rarely accounts for more than 1% of the annual total of daily pollen concentrations measured in a city; however in areas where these trees are widely used as ornamentals the amounts collected may be high enough to cause allergy symptoms.

Methods: Air samples taken with volumetric particle samplers Lanzoni VPPS 1000 (Lanzoni s.r.l., Bologna, Italy) show that there are differences in privet pollen concentrations measured in neighbourhoods with a high incidence of privet trees and in those taken at some distance from the source of emission.

Results: The results suggest that differences are due to the short dispersal range of the pollen grains once released from the plant, resulting from both the entomophilous nature of the plant and the large size of the pollen grains. Urban design, moreover, may play an important role in impeding pollen grain dispersion if the air cannot flow freely through long, narrow avenues. Another important consideration is that the last stages of the flowering period of privet overlaps with the flowering period of olive trees, the main allergen in the area. The fact that the two pollen types share common allergens means that there may be a cross‐reaction between olive tree pollen and privet pollen.

Conclusions: Privet pollen should be considered as a potential causative agent of local allergy problems in areas where its presence is extensive and is in combination with other allergens.
The effects of exogenous analgesia in a patient with borderline personality disorder (BPD) and severe self‐injurious behaviour
Authors: Thürauf Norbert J. , Washeim Heike A.
Published: July 2002

In order to analyse the effects of potent exogenous analgesia with opioids in borderline personality disorder (BPD), we present a case report in which the application of morphine abolished the perception of pain during self‐injury and intensified self‐injurious activities. On the basis of our observations, we concluded that the use of potent analgesics might aggravate psychopathology in BPD. Copyright 2000 European Federation of Chapters of the International Association for the Study of Pain
Short‐Term Changes in Heat Tolerance in the Alpine Cushion Plant Silene acaulis ssp. excapa [All.] J. Braun at Different Altitudes
Authors: Neuner G. , Buchner O. , Braun V.
Published: July 2002

Abstract: The habit of cushion growth positively affects plant temperature but at the same may increase the risk of occasional overheating. In order to determine the adaptive response to short‐term heat stress, we exposed S. acaulis cushions at field sites to controlled heat treatments using infrared lamps. Natural diurnal changes in heat tolerance were monitored at alpine sites and at a site distinctly below the natural distribution boundary, where higher temperatures were expected. The range of heat tolerance limits in summer, 45.5 ‐ 54.5 °C (9 K), exceeded that reported for other alpine species (0.1 ‐ 5 K) and even that for total seasonal changes (5 ‐ 8 K). Heat tolerance either increased or decreased on most days (80 %). The maximum diurnal increase was + 4.7 K. Under the experimental conditions heat hardening started at leaf temperatures around 30 °C and proceeded at mean rates of 1.0 ± 0.5 K/h. The onset of functional disturbances in photosystem II also occurred at 30 °C. Heating rates exceeding those naturally found above 30 °C (> 10 K/h) appeared to retard heat hardening. During summer average leaf temperature maxima were 12.4 K (600 m) and 13.0 K (1945 m) higher than air temperature which corroborates the heat trapping nature of cushion plants. At 600 m, as compared to 1945 m, cushions experienced significantly higher leaf temperature maxima (+ 8.8 K) and exceeded 30 °C on most days (80 %). This resulted in a significantly higher heat tolerance (LT50) at 600 m (51.7 ± 0.2 °C) than at 1945 m (49.8 ± 0.2 °C). The fast short‐term changes of heat tolerance in summer help S. acaulis to cope with the occasional diurnal short‐term heat stress associated with cushion growth.
Photosynthesis, Chlorophyll Fluorescence and Within‐Canopy Distribution of Epiphytic Ferns in a Mexican Cloud Forest
Authors: Hietz P. , Briones O.
Published: July 2002

Abstract: Parameters associated with the photosynthetic performance of eight common epiphytic ferns in a Mexican cloud forest were investigated in relation to the distribution of these species within the canopy. If the substantial microclimatic gradients within tropical forest canopies provide microhabitats exploited by different epiphytic species, we would expect to find correlations between distribution and physiological traits. Maximum rates of CO2 uptake (Amax) and photon flux densities at light compensation points (LCP) were in the range of shade plants (Amax = 0.6 ‐ 5.2 μmol m‐2 s‐1; LCP = 4 ‐ 6.5 μmol m‐2 s‐1), but saturation light intensities were more typical for sun plants (270 ‐ 550 μmol m‐2 s‐1). Amax and nitrogen content per unit dry weight were correlated with the distribution of the species within the canopy, but LCP, apparent quantum yield and dark respiration were not. When leaves were left to desiccate, the fluorescence yield of dark‐adapted leaves (Y0) remained high until the relative water content (RWC) had dropped below 30 to 20 %. Fluorescence after short illumination with 200 μmol m‐2 s‐1 declined when RWC dropped below 70 to 40 %. After exposure to full sunlight for 1 h, Y0 of species growing in the outer canopy (Pleopeltis mexicana and Polypodium plebeium) and a plant characteristic of the mid‐canopy (Elaphoglossum petiolatum) recovered better than in species from shadier locations (Trichomanes bucinatum, Asplenium cuspidatum, Phlebodium areolatum). With the exception of Ph. areolatum and a species growing at both exposed and shaded sites (Polypodium puberulum), Y0 recovered at least partially after a loss of 80 ‐ 96 % of saturation water, with the humidity‐loving filmy fern (T. bucinatum) showing no signs of permanent damage at all. The results suggest that tolerance or avoidance of desiccation and high light may be at least as important in controlling the distribution of the species studied as photosynthetic performance without stress.
Photoemission study of the band bending and chemistry of sodium sulfide on GaAs (100)
Authors: Spindt C. J. , Besser R. S. , Cao R. , Miyano K. , Helms C. R. , Spicer W. E.
Published: July 2002

Recently, there has been a great deal of interest in Na2S⋅9H2O as a passivating chemical treatment for GaAs surfaces. It has been shown that it reduces the high surface recombination velocity characteristic of GaAs surfaces, and may offer hope for ‘‘unpinning’’ the surface Fermi level. We have used photoemission spectroscopy to study the band bending and chemistry of these overlayers on n-type GaAs (100). Identically prepared samples show the characteristic increase in the photoluminescence signal, and have also been characterized using surface conductivity measurements. We find using photoemission that the surface Fermi level of the treated wafer is still near midgap. We also observe the chemistry at the interface, and offer a possible explanation of the photoluminescence and surface conductivity data in terms of it and the advanced unified defect model.
Optical studies of InxGa1−xAs/GaAs strained-layer quantum wells
Authors: Huang K. F. , Tai K. , Chu S. N. G. , Cho A. Y.
Published: July 2002

Intense single-peak photoluminescences of free-exciton origin were observed in InxGa1−x As/GaAs strained-layer quantum wells with x ranging from 0.09 to 0.20. Band lineups in these strained-layer heterostructures were determined by the dependence of luminescence energy on the well thickness. The heterojunction discontinuity in the heavy hole valence bands was found to be about 30% of the gap difference and independent of x. Exciton-phonon coupling was determined by temperature-dependent absorption measurements and the coupling strength was found to be similar to that of unstrained GaAs/AlxGa1−x As quantum wells.
Influence of oxygen pressure on the characteristics of the KrF-laser-induced plasma plume created above an YBaCuO superconducting target
Authors: Girault C. , Damiani D. , Aubreton J. , Catherinot A.
Published: July 2002

The laser-induced plasma plume created above an YBaCuO superconducting target by a KrF laser beam (248 nm) is investigated by time-resolved spectroscopy under an oxygen atmosphere. The influence of the oxygen partial pressure on the ejection velocities of the ablated species and on the relaxation of atomic and molecular excited species is particularly studied.
Excited-state absorption in HgBr
Authors: Schloss J. H. , Eden J. G.
Published: July 2002

The photoabsorption spectrum of the lowest ion pair state (B2Σ+1/2 ) of HgBr has been measured in the visible and ultraviolet (280≤λ≤480 nm) by laser excitation spectroscopy. Several previously unreported bands, peaking at 289, 302, 318, 330, 340, 364–373, and 401 nm, are observed and provide a stringent test for ab initio calculations of the excited state interaction potentials for the diatomic radical. A highly structured band lying between ∼444 and 470 nm confirms the observations of D. P. Greene, K. P. Killeen, and J. G. Eden [J. Chem. Phys. 85, 3188 (1986)] in a laser discharge. Also, the spectra fully resolve the apparent discrepancy between recent, unsuccessful attempts to produce a HgBr laser by flashlamp pumping the B←X band and experiments in which short pulse (8–25 ns) laser excitation of this transition has generated 502 nm coherent radiation with an energy conversion efficiency exceeding 20% [D. P. Greene, K. P. Killeen and J. G. Eden, Appl. Phys. Lett. 48, 1175 (1986)].
Magnetic force microscopy of thin Permalloy films
Authors: Mamin H. J. , Rugar D. , Stern J. E. , Fontana R. E. , Kasiraj P.
Published: July 2002

We have imaged naturally occurring domains in soft magnetic films using the force microscope. Classic closure structures were seen in both sputtered and plated Permalloy films. These structures were compared to optical Kerr micrographs of the same films, with generally good correspondence. The force microscope had sufficient sensitivity and resolution to observe magnetic details such as ripple structure and a Bloch line. Clear evidence of tip-induced wall motion was seen when the tip-to-sample separation was less than about 100 nm.
Saturation of the light-induced defect density in hydrogenated amorphous silicon
Authors: Park H. R. , Liu J. Z. , Wagner S.
Published: July 2002

We report new experimental results on the saturation of the light-induced defect density in hydrogenated (and fluorinated) amorphous silicon. The films were illuminated near room temperature up to 5000 h with bandpass filtered red light at a carrier generation rate G of 5×1020 cm−3 s−1, or up to 20 h with Kr+ laser light (λ=647.1 nm) at G=3×1022 cm−3 s−1. The bulk defect densities Ns saturate in both cases in the vicinity of 1017 cm−3. The saturation values are almost independent either of G or of temperature in the range from room temperature to about 70 °C. The illumination time to reach saturation is approximately proportional to 1/G2. These results are discussed within the framework of existing models for the light-induced defects.
Levitation properties of the YBa2Cu3Ox and Tl-Ba-Ca-Cu-O superconducting systems
Authors: Weeks David E.
Published: July 2002

A torsion balance is used to measure the levitation force on a magnet as a function of height above bulk samples of the YBa2Cu3Ox (Tc∼90 K) and Tl-Ba-Ca-Cu-O (Tc∼110–120 K) superconducting systems. Measurements of magnetic shielding and trapped magnetic fields are also made.
Heat treatment of wires on the basis of the high T
c superconductor YBa2Cu3Ox
Authors: Müller P. , Schubert M. , Rodig Ch. , Fuchs G. , Fischer K.
Published: July 2002

Ag-sheathed powder-in-tube wires on the basis of the high Tc superconductor YBa2Cu3Ox are produced by a drawing process. After cold working, the wires are not superconducting. By heat treatment at temperatures >900 °C, lattice defects are healed and the contact between the grains is improved. After this heat treatment the wires are slowly cooled in an O2 atmosphere in order to adjust the optimum O2 stoichiometry. The annealing temperature has a strong influence on the attainable critical current density. By annealing a wire with 420 ppm carbon content at 950 °C, jc values of 5020 A/cm2 at 4.2 K and 1130 A/cm2 at 77 K were achieved. Drastically reduced critical current densities in wires with high carbon content demonstrate the importance of a low carbon content for achieving high critical current densities in YBa2Cu3Ox .
Infrared spectra and electron spin resonance of vanadium deep level impurities in silicon carbide
Authors: Schneider J. , Müller H. D. , Maier K. , Wilkening W. , Fuchs F. , Dörnen A. , Leibenzeder S. , Stein R.
Published: July 2002

Trace impurities of vanadium in Lely-grown silicon carbide single crystals have been detected by their strong, polytype-specific photoluminescence in the 1.3–1.5 μm near-infrared spectral range, as well as by infrared absorption. The spectra arise from the intra-3d-shell transitions 2E(3d1)→2T2(3d1) of V4+Si(3d1). Electron spin resonance reveals that VSi in SiC acts as a deep acceptor, V4+Si(3d1)/V3+Si(3d2)−̂A0/A−, and possibly also as a deep donor. The role of vanadium as minority-carrier lifetime killer in SiC-based optoelectronic devices is suggested from these data.
Large- and small-signal gain characteristics of 1.5 μm multiple quantum well optical amplifiers
Authors: Eisenstein G. , Koren U. , Raybon G. , Koch T. L. , Wiesenfeld J. M. , Wegener M. , Tucker R. S. , Miller B. I.
Published: July 2002

We report large- and small-signal gain characteristics of 1.5 μm multiple quantum well optical amplifiers. We demonstrate a 350-μm-long amplifier with a peak gain of 15 dB. At a wavelength where the small-signal gain is 13.5 dB, the 3 dB saturation output power is as large as 45 mW. The 3 dB saturation output energy is 5.1 pJ and the calculated gain recovery time is 57 ps. We also demonstrate a 625-μm-long device with a gain of 19 dB and a saturation output power of 42 mW.
Influence of barrier inhomogeneities on noise at Schottky contacts
Authors: Güttler Herbert H. , Werner Jürgen H.
Published: July 2002

Electronic properties of Schottky diodes depend sensitively on spatial inhomogeneities of the metal/semiconductor interface. We find that, contrary to previous theories for low-frequency noise, the electronic properties of Schottky contacts cannot be understood if one neglects spatial fluctuations of the Schottky barrier height. Our systematic investigation of several silicide/silicon diodes yields as an empirical law that excess noise increases drastically when the standard deviation σs of the spatial distribution of Schottky barrier heights exceeds the critical threshold value of 2kT.
Generation of 41 mW of blue radiation by frequency doubling of a GaAlAs diode laser
Authors: Kozlovsky W. J. , Lenth W. , Latta E. E. , Moser A. , Bona G. L.
Published: July 2002

A monolithic ring resonator of KNbO3 was used for efficient frequency doubling of a 856 nm GaAlAs diode laser. A special electronic servo technique was devised to lock the diode laser frequency to the KNbO3 cavity so that stable generation of blue output was obtained. With 105 mW of incident near-infrared power, 41 mW of 428 nm radiation were produced. The conversion efficiency from electrical input power into the diode laser to blue output was ∼10%.
Effects of rapid thermal annealing and SiO2 encapsulation on GaInAs/AlInAs heterostructures
Authors: O’Brien S. , Shealy J. R. , Bour D. P. , Elbaum L. , Chi J. Y.
Published: July 2002

Substantial blue shifts in the transition energies of GaInAs/AlInAs single quantum wells were observed due to localized SiO2 capping and rapid thermal annealing at temperatures between 750 and 900 °C. In contrast to previously reported results, regions capped with SiO2 exhibited blue shifts up to 74 meV while regions with no SiO2 showed minimal shifting. With this band-gap change, a lateral index change of approximately −0.6% is anticipated making this process suitable for index-guided lasers. Samples also exhibited up to 15-fold increases in PL efficiencies due to the annealing process. The dependence of energy shifts and PL efficiencies is studied by measuring room-temperature and low-temperature photoluminescence.
New insights on the electronic properties of the trivalent silicon defects at oxidized 〈100〉 silicon surfaces
Authors: Vuillaume Dominique , Goguenheim Didier , Vincent Gilbert
Published: July 2002

We perform a deep level transient spectroscopy (DLTS) measurement of the band-gap energy distribution of the trivalent silicon defects (Pb centers) on as-oxidized 〈100〉 silicon wafers. By comparison with the 〈111〉 silicon surface, we isolate the energy distribution of the Pb1 center. Its acceptor level is found at 0.42 ± 0.02 eV from the conduction band while the acceptor level for the 〈100〉 Pb0 center is found at 0.22 ± 0.01 eV, a value smaller than at the 〈111〉 surface (0.33 ± 0.01 eV). We obtain new results about the capture cross sections of the 〈100〉Pb centers by energy-resolved DLTS trap filling experiments. The electron capture cross section of 〈100〉Pb1 is determined for the first time (5×10−16 cm2), while the electron capture cross section for 〈100〉 Pb0 (8×10−15 cm2) is found to be in agreement with earlier results.
Surface-energy-driven secondary grain growth in thin Sb films
Authors: Chou L. H.
Published: July 2002

Deposition rates and film thicknesses have been observed to be a key parameter for the grain growth and surface-energy-driven secondary grain growth of the as-deposited thin Sb films prepared by thermal evaporation. At a low deposition rate and thinner-film thickness (∼260 Å), (003) grains which have the lowest surface energy are observed to account for approximately 90% of the microstructure. Whereas at high deposition rate and greater film thickness (∼1300 Å), an almost random grain orientation was observed from x-ray diffraction data. After thermal annealing at 450 °C, secondary grains grew to show preferred orientation in all the films. Also, film thickness has been found to be an important factor on the succeeding microstructure after thermal annealing.
H− enhancement process in a multicusp ion source operated with a barium insert structure
Authors: Leung K. N. , van Os C. F. A. , Kunkel W. B.
Published: July 2002

It has been demonstrated that the H− output current from a small multicusp source can be substantially enhanced if the hydrogen plasma is seeded with barium. Operating with a barium washer insert at the extraction aperture, it is found that the extractable H− current is increased by a factor of 3 if the insert bias potential is optimized. By use of a mixture of xenon and hydrogen gas, it is further demonstrated that the positive hydrogen ions are responsible for the observed H− enhancement.
Influence of silicon oxide on the morphology of HF-etched Si(111) surfaces: Thermal versus chemical oxide
Authors: Jakob P. , Dumas P. , Chabal Y. J.
Published: July 2002

Infrared reflection-absorption measurements of the Si-H stretching vibrations of HF-etched Si(111) surfaces show that the structure of the H-passivated surfaces depends strongly on the nature of the initial silicon-oxide layer. For similar etching conditions, thermal oxides lead to much flatter surfaces than chemical oxides. A new processing sequence involving the removal of thermal oxide by buffered HF (pH=5), followed by etching in a 40% ammonium-fluoride solution, produces a remarkably homogeneous H/Si(111)-(1×1) surface, characterized by a 0.05 cm−1 broad Si-H stretch-mode.
Suppressed photocurrent multiple-quantum-well optical modulators by proton implantation
Authors: Woodward T. K. , Tell B. , Knox W. H. , Stark J. B.
Published: July 2002

We investigate the reduction of power dissipation in absorptive semiconductor optical modulators via reduction in photocurrent. We present experimental results for proton implantation of p-i-n-multiple-quantum-well modulators to levels of 1×1012, 1×1013, and 1×1014 cm−2. We find that photocurrent can be significantly reduced with moderate reduction in modulation performance relative to the unimplanted device. Application to asymmetric self-electro-optic devices is demonstrated.
X-ray generation by high irradiance subpicosecond lasers
Authors: Kyrala G. A. , Fulton R. D. , Wahlin E. K. , Jones L. A. , Schappert G. T. , Cobble J. A. , Taylor A. J.
Published: July 2002

We have studied the interaction of 290-fs, 308-nm laser pulses with aluminum targets at irradiances exceeding 5×1018 W/cm2. The x-ray spectrum is dominated by the H- and He-like lines from aluminum, with the brightest lines radiating 0.8% of the incident laser light energy. This fraction is close to that measured at 50 times less irradiance, but occurs at a slightly higher ionization stage. The x rays are emitted from a region of subcritical electron density at 3–6×1021 W cm−3. The radiance of the 1.73-keV Lα line is measured to be 4×1012 W/cm2/sr.
Adsorption and decomposition of diethylgermane on Si(111) 7×7
Authors: Coon P. A. , Wise M. L. , Walker Z. H. , George S. M. , Roberts D. A.
Published: July 2002

Germanium was deposited on Si(111) 7×7 by the adsorption and thermal decomposition of diethylgermane [(CH3CH2)2GeH2] (DEG). The DEG reaction products were CH2■CH2 and H2, which desorbed at 700 and 800 K, respectively, as observed by laser-induced thermal desorption and temperature programmed desorption techniques. The desorption of atomic Ge was also monitored at approximately 1200 K. The production of ethylene was consistent with a β-hydride elimination mechanism for the surface ethyl groups, i.e., Ge—CH2CH3→GeH+CH2■CH2. The initial sticking coefficient of DEG decreased with increasing surface temperature and a saturation coverage was obtained after exposures of E≳700 L at 200 K. This saturation behavior indicates that DEG may be useful for the controlled growth of Ge atomic layers on silicon surfaces.
X-ray reflectivity analysis of giant-magnetoresistance spin-valve layered structures
Authors: Huang T. C. , Nozieres J.-P. , Speriosu V. S. , Lefakis H. , Gurney B. A.
Published: July 2002

The amount of intermixing at the interfaces of sputter-deposited spin-valve layered structures, comprising Si/Ta (50 Å)/NiFe (75 Å)/Cu (22.5 Å)/NiFe (50 Å)/FeMn (110 Å)/Ta (50 Å), were obtained from least-squares refinement of x-ray reflectivity data. The observations were modeled by layers of nominal composition with compositional inhomogeneity at the interfaces. Layer thicknesses deduced from x-ray analysis were generally within a few percent of the nominal values. Interface widths between the two NiFe layers and the Cu spacer were 6.2-7.4 Å, indicating intermixing of atoms of about three monolayers at the interfaces. A 10.0-Å interface width was found at the FeMn interface suggesting a mixed-phase layer of α- and γ-FeMn. Layer densities, except those of the less dense Ta underlayer and the oxidized Ta surface, agreed to within 10% of bulk values. The results were in agreement with those obtained from closely related Si/Ta/NiFe/Cu/NiFe/Ta, Si/Ta/NiFe/Cu/Ta, Si/Ta/NiFe/Ta, and Si/Ta films.
Polarization effect on infrared absorption of oxygen precipitates in silicon
Authors: Borghesi A. , Pivac B. , Sassella A.
Published: July 2002

High-spatial resolution Fourier transform infrared spectroscopy permitted us to study the effects of incident light polarization on the absorption band related to aggregates of SiO2 disk-shaped precipitates present in annealed (100) Czochralski silicon samples. This is the first report documenting the strong dependence of such a band intensity on light polarization. Experimental results were compared with the simulation obtained using the effective medium theory. From this comparison we deduce that the precipitates only lie on the planes among {100} which are parallel to the wafer surface. This result can be related to the difference between the 〈100〉 direction and those crystallographically equivalent, introduced by the ingot growth process.
Single-frequency optical parametric oscillator
Authors: Bosenberg W. R. , Guyer D. R.
Published: July 2002

An optical parametric oscillator operating on a single longitudinal mode of its resonator is described. Using KTP as the nonlinear optical material and a grazing-incidence-grating resonator, single-frequency linewidths of 0.02 cm−1 are achieved. The device, pumped at 532 nm, was tuned over 0.7–0.9 μm (signal branch) and 1.3–2.2 μm (idler branch), and operated with up to 3 mJ of output corresponding to an external photon conversion efficiency of 12%.
Four wavelength distributed feedback ridge waveguide quantum-well heterostructure laser array
Authors: Miller L. M. , Beernink K. J. , Hughes J. S. , Bishop S. G. , Coleman J. J.
Published: July 2002

A four-wavelength strained-layer InGaAs-GaAs-AlGaAs distributed feedback ridge waveguide quantum-well heterostructure laser array, with a lasing emission wavelength separation of ∼16 Å between adjacent emitters, is described. The four-wavelength array requires only a single MOCVD growth step. Lateral optical confinement is achieved with dry-etched lateral third-order gratings. Each element operates in the fundamental lateral mode with a near-field FWHM of 2.6±0.1 μm and the entire width of the near-field pattern is <80 μm.
Formation and characteristics of hard magnetic materials: Pr(Mo,Fe)12Nx
Authors: Yang Ying-chang , Pan Qi , Zhang Xiao-dong , Yang Jun , Zhang Ming-hou , Ge Sen-lin
Published: July 2002

We succeed in stabilizing the PrMo1.5Fe10.5 compounds and their nitrides with ThMn12-type structure. The single phase was identified by using x-ray diffraction technique and thermomagnetic measurements. In PrMo1.5Fe10.5Nx, the c-axis is the easy magnetization direction from 0 K to Curie temperature. The anisotropy field is up to 147 KOe at 1.5 K and 110 KOe at room temperature. In combination with a high Curie temperature of 640 K and a large saturation magnetization of 141.70 emu/g, these intrinsic magnetic properties are favorable for permanent magnet applications. As a preliminary attempt, a coercive force of 3.0 and 10.0 KOe was obtained at 300 and 1.5 K, respectively, by using hydrogenation disproportionation and desorption (HDD) processing.
Characterization of deep level defects in thermally annealed Fe-doped semi-insulating InP by photoinduced current transient spectroscopy
Authors: Kalboussi A. , Marrakchi G. , Guillot G. , Kainosho K. , Oda O.
Published: July 2002

Photoinduced current transient spectroscopy has been used to show the effect of thermal annealing on deep level defects in semi-insulating Fe doped InP wafers. The annealing experiments have been accomplished in an infrared image furnace during 15 min at temperatures ranging from 663 to 820 °C. We show that this treatment leads to the formation of four deep traps named T1–T4 having the following activation energies: 0.14, 0.21, 0.41, and 0.53 eV, respectively. We show that the thermal anneal at high temperature leads to deterioration of the electrical properties of the material.
THz pulses from the creation of polarized electron-hole pairs in biased quantum wells
Authors: Planken Paul C. M. , Nuss Martin C. , Knox W. H. , Miller D. A. B. , Goossen K. W.
Published: July 2002

We report generation of coherent terahertz electromagnetic transients from GaAs/Al0.3Ga0.7As quantum wells in perpendicular fields. Although, at low temperature, the quantum well barriers suppress the transport current perpendicular to the layers by at least two orders of magnitude compared to bulk, we observe terahertz signals that are comparable in strength to those generated from bulk GaAs surfaces. This directly proves that the field-induced polarization of photoexcited electron-hole pairs is an important mechanism for the generation of terahertz radiation at semiconductor surfaces.
Sr2AlTaO6 films for multilayer high-temperature superconducting device applications
Authors: Findikoglu A. T. , Doughty C. , Bhattacharya S. , Li Qi , Xi X. X. , Venkatesan T. , Fahey R. E. , Strauss A. J. , Phillips Julia M.
Published: July 2002

Thin films of Sr2AlTaO6 (SAT) and multilayers of YBa2Cu3O7 (YBCO)/SAT have been grown by pulsed laser deposition on [001] LaAlO3 substrates. X-ray diffraction shows that SAT grows on [001] LaAlO3 with the c-axis oriented normal to the substrate plane. X-ray rocking curve and Rutherford backscattering channeling measurements on SAT films yield full width at half maximum of <0.3° and minimum backscattering yield χmin of 5%–7%, respectively, indicating good crystallinity. The real part of the dielectric constant εr is found to be ∼23–30, with ∼6×107 V/m static breakdown electric field. Both the dielectric constant and the static breakdown field show negligible temperature dependence between 10 and 300 K. A 100 nm×10 μm×50 μm YBCO film on SAT shows zero-field critical current density of ∼1.3×106 A/cm2 at 77 K, with a superconducting transition temperature Tc0 of ∼89.2 K.
Phonon-induced electron localization and magnetic-field effects in a double quantum dot
Authors: Nakano Aiichiro , Kalia Rajiv K. , Vashishta Priya
Published: July 2002

Resonant tunneling of an electron through a double quantum dot is studied in the presence of phonon scattering and magnetic field. The coupled time-dependent Schrödinger equations for an electron and longitudinal-optical phonons are solved numerically within a mean-field approximation. Phonon-induced electron localization is observed. A magnetic field reduces the buildup time of electron probability density in the dots, but increases the decay time associated with the resonant tunneling. Inelastic processes increase the decay time, but their effect on the buildup time depends on the strength of the magnetic field.
Depth profiling of the d33 nonlinear coefficient in annealed proton exchanged LiNbO3 waveguides
Authors: Bortz M. L. , Eyres L. A. , Fejer M. M.
Published: July 2002

We report depth profiling of the d33 nonlinear coefficient in annealed proton exchanged LiNbO3 waveguides using reflected second-harmonic generation from angle-lapped samples. At depths greater than the initial proton exchange depth the d33 coefficient retains nearly its bulk LiNbO3 value, but within the initial proton exchange region the value of d33 varies with annealing time. These results reconcile previous conflicting measurements of the d33 coefficient and explain the variation in the efficiency of guided wave frequency conversion devices with annealing.
In situ diagnostics of pulsed laser deposition of ferroelectric Pb(Ti0.48Zr0.52)O3 on Si
Authors: Iembo A. , Fuso F. , Allegrini M. , Arimondo E. , Berardi V. , Spinelli N. , Leccabue F. , Watts B. E. , Franco G. , Chiorboli G.
Published: July 2002

The transport of material from target to substrate has been monitored in the pulsed laser deposition of Pb(Ti0.48Zr0.52)O3 films on p-doped Si(100) using two in situ diagnostics, namely plume fluorescence spectroscopy and plume ion mass spectrometry. The as-grown PZT films are specular, with thicknesses which decrease from 350 to 250 nm on a radius 5 mm from the center and show a dielectric hysteresis with typical remanent polarizations and coercive fields of 0.2 μC/cm2 and 124 kV/cm, respectively. The analysis of the plume fluorescence emission and ionic yield indicates that oxidation of the ablated material occurs during transport from target to substrate and that, in order to grow ferroelectric thin films, the substrate should be located in the region of the plume where the relative concentrations of metal oxides and clusters increase.
Temperature-dependent electron mobility in GaN: Effects of space charge and interface roughness scattering
Authors: Joshi R. P.
Published: July 2002

We compute temperature-dependent electronic mobilities in GaN through Monte Carlo simulations. Bulk material having ionized impurities, and a quantum well structure are examined. Our values show good agreement with recently obtained experimental data on bulk GaN only when space-charge scattering is taken into account. Though a simple form for the internal potential variation has been used, more realistic space-charge distributions could easily be incorporated into the present simulation scheme. Mobilities for GaN quantum wells have also been obtained by explicitly taking account of interface roughness scattering. The predicted values yield a theoretical upperbound fairly close to measured data.
Temperature dependence of gain-guided vertical-cavity surface emitting laser polarization
Authors: Choquette Kent D. , Richie D. A. , Leibenguth R. E.
Published: July 2002

We show the polarization characteristics of gain-guided vertical-cavity surface emitting lasers are related to the temperature-dependent cavity optical resonance and laser gain spectral alignment. Simultaneous nearly degenerate orthogonal eigen polarization states are observed at and above lasing threshold. The partitioning of power between the linear polarization states is shown to depend on the relative spectral overlap of the cavity resonance of each state with the gain. Near the condition of cavity resonance/gain alignment, an abrupt switch in the dominant eigen polarization with a region of polarized output fluctuations is evident. Rotation of the eigen polarization directions relative to the crystal axes is also observed at temperatures where the gain is blue shifted from the cavity resonances.
Scanning near-field optical microscope for the imaging of magnetic domains in optically opaque materials
Authors: Silva T. J. , Schultz S. , Weller Dieter
Published: July 2002

We describe a scanning near-field optical microscope capable of magnetic imaging in optically opaque materials. The near-field probe is a ∼30 nm Ag particle, optically excited near the surface plasmon resonance frequency. The separation of the probe and sample is regulated by a Newton ring interferometer. The polarization rotation of the scattered light due to near-field magneto-optic interactions is measured. A two-dimensional image is presented of thermomagnetically recorded magnetic domains in a perpendicularly magnetized Co/Pt multilayer material with 0.5-μm-diam domains at one micrometer spacing. Images suggest a resolution of <100 nm.
Wavelength tuning in spherical liquid dye lasers by controlling the cavity Q values
Authors: Taniguchi Hiroshi , Tomisawa Humihiro
Published: July 2002

A method for wavelength tuning in spherical liquid dye lasers is reported, due to controlling cavity Q values by injection of scattering particles. The cavity Q value of the sphere dye lasers is controlled by varying the quantity of poly(methyl methacrylate) spheres in the spherical liquid laser solution. Results of the tuning are explained in terms of a general wavelength dependence determined by gain/loss characteristics in the microsphere lasers.
Odd–even effects of the polar anchoring strength in nematic liquid crystal on rubbed polyimide Langmuir–Blodgett films with alkyl chain lengths
Authors: Seo Dae-Shik , Kobayashi Shunsuke , Nishikawa Michinori , Kim Jae-Hyung , Yabe Yoshikazu
Published: July 2002

The odd–even effect of the alkyl chain length of rubbed polyimide Langmuir–Blodgett (LB) films on the extrapolation length of 5CB has been successfully evaluated by measuring polar anchoring strength. The extrapolation length of 5CB for rubbed PI-LB films with even numbers is small compared with odd numbers for alkyl chain lengths of greater than 7 carbons. The extrapolation length of 5CB on rubbed PI-LB films with odd numbers increases gradually as the temperature increases but tends to diverge near the clearing temperature ( Tc=35.3 °C). The extrapolation length diverges because of rapidly decreasing surface order near Tc. It is suggested that the polar anchoring strength on rubbed PI-LB films with an even number is strong because of relatively high surface ordering caused by more crystalline surfaces. Finally, it is concluded that the odd–even effects of the polar anchoring strength in NLCs are strongly related to the character of the polymer and observed clearly for long alkyl chain lengths.
Scanning plasmon optical microscope
Authors: Kim Y-K. , Lundquist P. M. , Helfrich J. A. , Mikrut J. M. , Wong G. K. , Auvil P. R. , Ketterson J. B.
Published: July 2002

A new scanning near-field optical microscopy based on the surface plasmon resonance is presented. Enhanced fields are localized at individual surface irregularities by the scattering of plasmons and the scattered plasmons produce a conical radiation. Variations in the conical radiation intensity caused by interactions between a raster-scanned probe tip and the enhanced fields are recorded and related to the surface topography, providing an optical image with lateral resolution exceeding the diffraction limit. This technique is compared to complementary atomic force microscopy and scanning tunneling microscopy measurements and potential advantages are discussed.