bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Diffusion of I Group Metal (Ag) on Characteristics of Metal/Porous Silicon Sensors
Authors: Dzhafarov T.D , Aydin S. , Oren D.
Published: March 2009

Current-voltage characteristics of Schottky-type Ag/Porous Silicon (Ag/PS) structures in
normal air, humid ambient and in different hydrogen-containing solutions (distilled water, freshwater,
Black sea-water, ethanol ad methanol) have been investigated. Generation of the opencircuit
voltage (Voc), short-circuit current (Jsc) up to 560 mV and 0.5mA/cm2, respectively, on
placing Ag/PS structures in hydrogen-containing solutions was discovered. This phenomenon is
reversible, i.e. placing and removal of Ag/PS structures cell from hydrogen-containing solutions is
accompanied by response and recovery of the Voc and Jsc parameters. It is shown that the thermal
annealing of the Ag/PS structure at 200oC for 10 min is accompanied by somewhat changes and
stabilization of Voc and Jsc parameters of Ag/PS sensors. The possible mechanisms related with
hydrogen-stimulated generation of voltage and diffusion-stimulated stabilization of the sensing
parameters of Ag/PS Schottky-type structures is suggested. Data received in this work indicate on
perspectivity of using Ag/PS structures as both the gas sensors and hydrogen cells.
Multiplicity of Nitrogen Species in Silicon: The Impact on Vacancy Trapping
Authors: Voronkov Vladimir V. , Falster Robert J.
Published: March 2009

Nitrogen in silicon is known to affect dramatically the properties of voids. A plausible
mechanism could be vacancy trapping by nitrogen interstitial species, mostly by the minor
monomeric species (N1) with only a negligible contribution of the major dimeric species (N2).
However, a more careful analysis of the published data shows that in Czochralski silicon no
vacancy trapping occurs at the void formation stage (around 1100oC). The implication is that the
trapping reaction, V + N1, although favoured thermodynamically, is of a negligible rate. Therefore,
the nitrogen effect on voids in Czochralski Si is entirely due to nitrogen adsorption at the void
surface. Quite a different mechanism operates in Float-Zoned crystals where voids are formed at
lower T. Here vacancy trapping by N2 seems to be responsible for void suppression.
Fundamental Interactions of Fe in Silicon: First-Principles Theory
Authors: Estreicher Stefan K. , Sanati Mahdi , Szwacki N. Gonzalez
Published: March 2009

Interstitial iron and iron-acceptor pairs are well studied but undesirable defects in Si as
they are strong recombination centers which resist hydrogen passivation. Thermal anneals often
result in the precipitation of Fe. Relatively little information is available about the interactions
between Fe and native defects or common impurities in Si. We present the results of first-principles
calculations of Fe interactions with native defects (vacancy, self-interstitial) and common impurities
such as C, O, H, or Fe. The goal is to understand the fundamental chemistry of Fe in Si, identify and
characterize the type of complexes that occur. We predict the configurations, charge and spin states,
binding and activation energies, and estimate the position of gap levels. The possibility of
passivation is discussed.
Theoretical Aspects on the Formation of the Tri-Interstitial Nitrogen Defect in Silicon
Authors: Fujita N. , Jones R. , Eberlein T.A.G. , Öberg Sven , Briddon Patrick R.
Published: March 2009

In this paper we investigate the formation of interstitial nitrogen trimers N3 which
have been suggested as a fast-diffusing species in silicon recently. Out-diffusion profiles of nitro-
gen show the involvement of at least two independent nitrogen related defects in the diffusion
process depending on the nitrogen concentration at different depths of the sample. When the
nitrogen concentration is small it is proposed that nitrogen trimers are formed in a two step
process. We present the structural properties of such a defect using density functional theory
and examine the energetics of the two proposed reactions leading to the formation of N3.
A Comparative Analysis of Structural Defect Formation in Si+ Implanted and then Plasma Hydrogenated and in H+ Implanted Crystalline Silicon
Authors: Nordmark Heidi , Ulyashin Alexander G. , Walmsley John Charles , Holmestad Randi
Published: March 2009

Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been used
to compare hydrogen defects formed in p doped [001] oriented Cz silicon samples which are H+
plasma treated , H+ implanted or Si+ implanted + H+ plasma treated. Samples were studied as
processed and after annealing at 250°C, 450°C and 600°C. It is found that 1 hour H+ plasma
treatment at 250°C produces a low density of large defects (~100 nm) in prefered {111} plans close
to the surface. H+ implantation at a dose of 3x1016 cm-2 produces high density of small (~ 20 nm)
mostly {100} platelets that after 1 hour annealing at 450°C result in microcrack formation. Lower
H+ implantation doses form very few microcracks at this temperature. Silicon implantation with a
dose of 1015 cm2 followed by 1 hour H+ plasma treatment at 250°C and 1 hour annealing at 450°C
produces similar microstructure and microcracks as the 3x1016 cm2 H+ implantation dose.
Properties of Si:Cr Annealed under Enhanced Stress Conditions
Authors: Misiuk Andrzej , Barcz Adam , Chow Lee , Surma Barbara , Bak-Misiuk Jadwiga , Prujszczyk M.
Published: March 2009

The effect of hydrostatic argon pressure equal to 105 Pa and 1.1 GPa applied to processing
at up to 1270 K (HT) of Si:Cr samples prepared by Cr+ implantation (dose 1x1015 cm-2, 200
keV) into (001) oriented Czochralski silicon, has been investigated by Secondary Ion Mass Spectrometry,
photoluminescence, X-ray and SQUID methods.
Cr+ implantation at this energy and dosage produces amorphous silicon (a-Si) near the implanted
ions range. Solid phase epitaxial re-growth (SPER) of a-Si takes place at HT. The Cr profile
does not depend markedly on HP applied during processing at 723 K. Si:Cr processed at up to 723
K indicates magnetic ordering. Annealing under 105 Pa at 873 K, 1070 K and 1270 K results in a
marked diffusion of Cr toward the sample surface. In the case of processing under 1.1 GPa this diffusion
is less pronounced, SPER of a-Si is retarded and the a-Si/Si interface becomes enriched with
Cr. The Cr concentration in Si:Cr sample processed at 1270 K under 1.1 GPa forms two distinct
maxima, the deeper one at 0.35 μm depth.
Effect of Grown-In Defects on the Structure of Oxygen Precipitates in Cz-Si Crystals with Different Diameter
Authors: Litovchenko V.G. , Lisovskyy I.P. , Claeys Cor , Kladko V.P. , Zlobin S.O. , Muravska M.V. , Efremov O.O. , Slobodjan M.V.
Published: March 2009

IR-spectroscopy with computer analysis of the shape of the Si-O absorption band,
electron microscopy, X-rays diffraction and measurements of unsteady photoconductivity timedecay
under band-to band excitation were used to investigate the influence of defects in different
diameter (40 – 300 mm) Si ingots on the oxygen precipitation due to two-stage annealing (750 оС +
1050 оС). It is shown that large size Cz-Si ingots have a relatively low concentration of electrically
active micro-defects, containing small (0.06 – 0.1 μm) dislocation loops. During thermal treatments
this leads to the formation of a low stressed oxide phase (SiO2) with an enhanced thermo-stability.
The precipitates in small size ingots, however, contain distorted 4-fold rings of SiO4 tetrahedra.
DLTS and PR Studies of Partially Relaxed InGaAs/GaAs Heterostructures Grown by MOVPE
Authors: Gelczuk Łukasz , Jóźwiak Grzegorz , Motyka Marcin , Dąbrowska-Szata Maria
Published: March 2009

The studies of electrical activity of deep electron traps and the optical response of
partially-strain relaxed InxGa1-xAs layers (x=5.5%, 7.7% and 8.6%) grown by metalorganic vapourphase
epitaxy (MOVPE) have been performed by means of deep-level transient spectroscopy
(DLTS) and photoreflectance (PR). DLTS measurements revealed two electron traps. One of the
trap has been attributed to electron states at α-type misfit dislocations. The other trap has been
ascribed to the EL2 point defect. The PR spectra at room temperature were measured and analysed.
By applying the results of theoretical calculations which include excitonic and strain effects, we
were able to estimate the extent of strain relaxation and the values of residual strain in the partially
relaxed epitaxial layers.
Regular Dislocation Networks in Si. Part II: Luminescence
Authors: Mchedlidze Teimuraz , Wilhelm T. , Yu X. , Arguirov Tzanimir , Jia G. , Reiche Manfred , Kittler Martin
Published: March 2009

Regular dislocation networks formed as a result of the direct bonding of Cz-Si wafers with oxide
remnants on the pre-bonding surfaces were investigated. Besides the dislocation network, oxide
precipitates were detected at the bonding interface. The precipitate density across the network was
~5×1010 cm-2, except small irregularly distributed circular areas, several mm in diameter, where the
density was remarkably lower (<5×108 cm-2). The dislocation network structure was not affected by
the change in the precipitate density. Photoluminescence spectroscopy (PL) and light beam induced
current (LBIC) mapping were applied for characterization of such dislocation networks. For the
locations with high precipitate density, PL signal from dislocations and that from the band-to-band
transitions were enhanced. On the other hand, the LBIC results indicated that oxide precipitates are
active recombination centers and thus should suppress the observed radiative transitions. The
controversy can be explained in the assumption that the D-band PL signal increases due to
scattering of excitation light by the precipitates and due to related expansion of the excitation area
of the dislocation network. The light reflection from the precipitate layer also enhances the detected
band-to-band PL signal. The shape of PL spectra from the samples in the range of photon energies
0.75 – 1.15 eV was not influenced by the oxide precipitates.
Dislocation Photoluminescence in Silicon and Germanium
Authors: Shevchenko S. , Tereshchenko A.N.
Published: March 2009

Dislocation photoluminescence (DPL) is studied at 4.2K in plastically deformed
germanium single crystals containing predominantly 60fl dislocations of “relaxed” morphology. The
DPL spectra were deconvolved into Gaussian (Gm) lines of two groups over the range 0.5-0.6 eV.
One of these lines corresponds to the radiation of 60fl dislocations with the equilibrium stacking
fault width F0. To clarify the origin of the other Gm lines, the effect of both the dislocation density
ND, ranging from106 to 109 cm-2, and the annealing at temperatures above 600flC on the intensity of
Gm lines was investigated. The origin of different lines in the DPL spectra of germanium and silicon
is discussed.
Silicon Doped with Lithium and Magnesium from the Melt for Terahertz Laser Application
Authors: Abrosimov Nikolay V. , Nötzel N. , Riemann H. , Irmscher K. , Pavlov Sergeij G. , Hübers Heinz Wilhelm , Böttger Ute , Haas Philippe M. , Drichko N. , Dressel M.
Published: March 2009

Silicon crystals, doped with moderate concentration of magnesium or lithium, have been
grown for application as optically pumped donor silicon lasers for the terahertz spectral region. The
pedestal growth technique accompanied with axial-loaded dopant pills enabled manufacturing of
large silicon crystals with a homogeneous donor distribution in the range from 1014 to 1016 cm-3, as
required for intracenter silicon lasers. Terahertz-range photoluminescence from the grown crystals
has been observed.
Investigation of the Temperature Degradation and Re-Activation of the Luminescent Centres in Rare Earth Implanted SiO2 Layers
Authors: Prucnal S. , Rebohle L. , Skorupa Wolfgang
Published: March 2009

The temperature quenching mechanisms of the electroluminescence (EL) and the reactivation of the
rare earth luminescent centres by the flash lamp annealing (FLA) made after hot electron injection
into the SiO2 layer implanted by Tb and Gd was investigated. An increase of the temperature from
room temperature up to 150oC reduces the gate voltage of about 3 V and increases the rate of the
EL quenching process and the degradation of the Metal-Oxide-Silicon Light Emitting Diode
(MOSLED) structure by a of factor of three. On the other hand, the post-injection FLA reactivates
the RE centres switched off by electrons trapped around them during hot electron impact excitation,
increasing the operating time of the MOSLEDs devices.
Effect of Various Treatments on Light Emission Properties of Si-Rich-SiOx Structures
Authors: Baran M. , Korsunska N. , Khomenkova L. , Stara T. , Khomenkov V. , Goldstein Y. , Savir E. , Jedrzejewski J.
Published: March 2009

The effect of preparation conditions and annealing treatment on Si-rich-SiOx layers was
investigated. It was observed that oxygen plays important role in the creation of light-emitting
centres. It was found that the emission in the green-orange spectral range is connected with silicon
oxide defects which contain dangling bonds. At the same time PL band in the infrared spectral
range is caused by recombination of carriers in amorphous silicon or nanocrystalline one. It is
shown that modification of defect content under various treatments gives the possibility to control
the emission properties of the layers.
Passivation of Si and SiGe/Si Structures with 1-Octadecene Monolayers
Authors: Antonova I.V. , Gulyaev M.B. , Soots R.A. , Seleznev V.A. , Prinz V.Ya.
Published: March 2009

The electrical properties of structures included 1-octadecene (CnH2n, n=18) monolayers
deposed onto the oxide-free silicon surface or Si/SiGe/Si layers were analyzed as a function of
surface pretreatment (hydrogen- or iodine-terminated silicon surface) and layer deposition regime
(thermal- or photo-activated process). Two types of traps (for electrons and holes) were found at the
interface between the monolayers and substrate. The density of traps was shown to depend on the,
H- or I-termination of the silicon surface, the illumination intensity and deposition time during
photo-activated deposition, and the temperature of thermal-activated deposition. The optimal
regimes can be chosen for minimization of the surface charge in the structures covered with 1-
octadecene monolayers, which provides a high conductivity of thin near-surface layers.
Aging Phenomena in the Removal of Nano-Particles from Si Wafers
Authors: Vereecke Guy , Veltens J. , Xu Kai Dong , Eitoku Atsuro , Sano Kenichi , Arnauts Sophia , Kenis Karine , Snow James , Vinckier Chris , Mertens Paul W.
Published: March 2009

With the continuous shrinkage of critical sizes in semiconductor manufacturing, nano-particles smaller than 100-nm are becoming a potential threat to devices in chips. Storage of wafers contaminated during process steps often results in a decrease of particle removal efficiency in subsequent clean, a phenomenon referred to as aging. In this work, the influence of aging on the removal of silica and silicon nitride nano-particles from hydrophilic Si wafers was studied for different storage conditions. Trends observed for aging as a function of particle size and for different tools indicated that aging will become an issue for critical cleans where substrate etching must be kept very low and the physical component of the clean must be decreased to prevent damage to fine structures. Controlling the relative humidity during storage helped in lowering the effect of aging.
Implications of the Selectiveness of Cu Chelators on Cu0, Cu(I)O and Cu(II)O Powders
Authors: Macdougall Jennie , Reid Chris , McGhee Larry
Published: March 2009

The time and stoichiometric ratio dependence on dissolution of Cu from Cu(I)O and Cu(II)O and
metallic Cu was investigated for a series of known Cu chelators. This was monitored by ICP-OES
and UV-VIS. A notable difference in the rate of reaction for Cu(I)O vs Cu(II)O was observed and
the impact of a copper adduct precipitating from solution discussed as this may present a redeposition
issue for Cu surface cleaning. Additionally these chelators were found to selectively
favour Cu0 and typically showed higher solution levels of Cu when exposed to the oxides.
Antifungal Effectiveness of Nanosilver Colloid against Rose Powdery Mildew in Greenhouses
Authors: Kim Hae Sic , Kang Hyun Suk , Chu Gyo Jin , Byun Hong Sik
Published: March 2009

The antifungal effectiveness against rose powdery mildew using antimicrobial nanosilver
colloidal solution was investigated. Double-capsulized nanosilver was prepared by chemical
reaction of silver ion with aid of physical method, reducing agent and stabilizers. The average
diameter of nanosilver was about 1.5 nm. They were highly stable and very well dispersive in
aqueous solution. The Transmission electron microscopy and UV-vis spectrometer were used
for measurements of size analysis and their stability, respectively. The nanosilver colloidal
solution of concentration of 5000 ppm was diluted in 10 ppm of 500 kg and sprayed at large
area of 3306 m2polluted by rose powdery mildew. The white rose powdery mildew fade out
above 95 % after 2 days and was not recurred for a week. The antifungal effects were observed
by an optical microscope and photographs.
Low-Temperature Fabrication of Polycrystalline Yttrium Aluminum Garnet Powder via a Mechanochemical Solid Reaction of Nanocrystalline Yttria with Transition Alumina
Authors: Jung Hyun Gi , Cheong Young Hun , Han In Dong , Kim So Jin , Kang Sung Goon
Published: March 2009

Mechanical processing of nanocrystalline Y2O3 and transition alumina (AlOOH) was
performed, using a Spex mixer mill under atmospheric conditions, to synthesize yttrium aluminum
garnet (YAG, Y3Al5O12) powder at lower temperature. The reaction of nanocrystalline Y2O3 with
AlOOH was activated by mechanical energy and use of fine instead of heat energy, leading to the
direct formation of pure YAG without second phases at a lower temperature, 800°C, which is
significantly lower than that required by the conventional solid-state reaction process.
Can the Activated Carbon that is Currently Used in the NBC Protective Wear Be Replaced
Authors: Ramakrishnan Ramaseshan , Liu Ying Jun , Subramanian Sundarrajan , Ramakrishna Seeram
Published: March 2009

For ages, activated carbon has been unarguably the most preferred material for chemical
warfare protective clothing by armies across the globe. Although the morphology in which
it is used has changed from granular form to fiber form, there has not been much change in
the chemical composition or functionality (ASZM-TEDA grade). In this paper we
investigate to find out if there is a possibility of replacement of the activated carbon by
other materials. Before we find the answer to this question, it is important to reason out
why replacement is thought of in the first place.
Activated carbon is a versatile material that brings with it several good qualities like large
surface area, adsorptive nature, fire-resistant, robustness and availability of aplenty. Some
of its disadvantages include heavy weight and low breathability (moist activated carbon
will adsorb oxygen from the environment causing breathing difficulties). One other
disadvantage which is often overlooked by the user is the disposal of the suits after usage.
Activated carbon merely adsorbs the nerve and mustard agents and once they become
saturated, they are classified as hazardous materials necessitating safe disposal. The used
wear is normally sent back to the supplier of manufacturer where it would be essentially
decontaminated by bleaching and then disposed by incineration or landfill. Thus, if there
is a material that can ensure breathability is of light weight and has the capacity to
decontaminate the adsorbed warfare agents in situ, it would be ideal for use in the
protective clothing.
In this paper novel electrospun ceramic nanostructures are introduced which are capable
of reactive decontamination of nerve and mustard agents. The decontamination
efficiencies of the ceramic nanofibers are presented as tested against simulants of nerve
and mustard agents. Electrospinning was chosen as the fabrication method because it is a
simple traditional technique that is capable of manufacturing nano sized structures in a
large scale. Moreover, electrospun materials possess more activity due to their surface
charge density. The contribution of nano-size scale to the reactivity of the fibers is
shown. All these project the electrospun nanostructured ceramics as the best possible
substitutes to activated carbon.
Evaluation of Interfacial Fracture Behavior of HVAS Coating/Substrate System Using a Local Approach
Authors: Xu Lian Yong , Jing Hong Yang , Wei Jun , Zou Hui
Published: March 2009

In this paper, the local approach based on the Weibull stress criterion was used to investigate the interfacial fracture behavior between LX88A coating and Q345 steel. LX88A coating was deposited by high velocity electric arc spraying technology (HVAS). The finite element method (FEM) was used to analyze the stress-strain fields of the coating specimen which consisted of three different specimen geometrics or modes of loading. It was found that the Weibull stress for all specimen geometries was almost identical under the same fracture probability when the interfacial fracture initiation occurred for different specimen geometries. It showed that the geometry dependence on the interface brittle fracture toughness data can be reduced through application of the local approach, and the local approach can be used to describe the interfacial fracture behavior.
Influence of Thermal Cycling and Equivalent Heat Treatment on Amplitude Dependence of Internal Friction in Cu-Al-Mn Shape Memory Alloys
Authors: Mielczarek Agnieszka , Marczyk Marcin , Riehemann Werner
Published: March 2009

The influence of thermal cycling between - 196 °C and 200 °C and equivalent heat
treatment at 200 °C on the amplitude dependence of internal friction at room temperature has been
studied in as cast Cu – Al - Mn shape memory alloys with different chemical compositions. Using
X-ray diffraction one composition was found to be austenitic and two others martensitic with two
martensite types (2H and 18R) at room temperature. All specimens were thermally cycled for 100
times. During one thermal cycle the specimen underwent altogether two phase transformations one
in each direction. Thermal cycling causes microstructural changes in the specimens due to atomic
reordering, thermal stresses, which are generated in the martensitic state due to the anisotropy of
thermal expansion, or due to the nucleation and propagation of interphase cracks in parent phase.
During repeated thermal cycling the transition peaks obtained in mechanical spectroscopy became
narrower due to an enduring change of the microstructure and annealing effect at 200 °C. To
compare between the effects of thermal cycling and heat treatment one martensitic specimen was
annealed at 200 °C. For selected cycle numbers and heat treatment times the amplitude dependence
of damping was measured at room temperature. The influence of thermal cycling of martensitic
specimens on the damping level was found to be similar to the influence of heat treatment at
200 °C. It is most likely that the highest heat treatment temperature is more important for the
amplitude dependence of damping than the temperature change during thermal cycling. Cracks due
to thermal cycling were found in all cycled specimens. They have no significant effect on the
amplitude dependence of damping of the martensitic samples, whereas some small influence could
be observed in austenitic samples at room temperature.
Do Electromagnetic Pulses Induce the Relaxation or Activation of Microcracking Rate in Loaded Rocks?
Authors: Bogomolov Leonid , Zakupin Alexander
Published: March 2009

The work is devoted to the problem of role of ambient factors (external electromagnetic
field, in particular) in the process of ageing of mechanically burden nonmetallic solids (rocks). A
specific research point is the effect of temporary activation of Acoustic Emission (AE) of rocks
specimens during action of EM field pulses applied externally. Extended experimental studies of
responses of AE have been conducted to evince the changes in defects accumulation process in
loaded specimens due to external power impacts (EPI). The experiments have been held on
noiseless rheological machines available at Bishkek Geodynamic Research Center - RS RAS. We
have tested a number of specimens made of different materials and analyzed the temporal
dependence of AE activity during exposure in electric field and crossed electric and magnetic fields;
the compressive load being constant. The effect of AE stimulation by power pulses (triggering) has
been verified. The obtained results allow to distinguish two kinds of AE activation. The first kind
involves simultaneous well correlated growth of numbers of minor and major AEs (so-called selfconsistency
of temporal plots of activity of different range acoustic events). The second kind
represents dissimilar variations: the increment of activity of minor energy AEs, but the decrement
of those of major energy. The first kind of solids material responses to EPI is prevailing when the
compressive loads is under 0,85 of fracturing value. The episodes of dissimilar AE responses may
signify that electromagnetic control of defects accumulation process inside rocks is possible, in
principle.
High Temperature Mechanical Loss Spectrum of 3Y-TZP Zirconia Reinforced with Carbon Nanotubes or Silicon Carbide Whiskers
Authors: Ionascu Claudia , Schaller Robert
Published: March 2009

High temperature plasticity of fine-grained ceramics (ZrO2, Al2O3, etc) is usually
associated with a grain boundary sliding process. The aim of the present research is then to improve
the high-temperature mechanical strength of polycrystalline zirconia (3Y-TZP) through the
insertion of multiwalled carbon nanotubes (CNTs) or silicon carbide whiskers (SiCw), which are
susceptible to pin the grain boundaries. The effect of these nano-sized particles on grain boundary
sliding has been studied by mechanical spectroscopy.
Mechanical Spectroscopy and Neutron Diffraction Studies in Fe-Al-Si Alloys
Authors: Lambri O.A. , Pérez-Landazábal José Ignacio , Cuello G.J. , Cano J.A. , Recarte Vicente , Golovin Igor S.
Published: March 2009

Mechanical spectroscopy and neutron diffraction studies were performed on several
samples with compositions Fe - 25 at. % (Al + Si) and Fe - 15 at. % (Al + Si). It was found that the
solute grain boundary relaxation is strongly dependent on the degree of order in the sample. A
decrease in the orderdegree allows the development of a relaxation peak at around 1000 K during
cooling from 1200 K. In contrast, if the order degree is not decreased, the grain boundaries remain
locked and consequently the relaxation peak does not appear. The magnetic response both in the asquenched
and after thermal treatment states was also explored and correlated to the microstructural
state.
Mechanical Spectroscopy of the Fe-25Al-Cr Alloys in Medium Temperature Range
Authors: Golovin Igor S. , Rivière Andre
Published: March 2009

Fe3Al intermetallic compounds and several (Fe,Cr)3Al alloys with Cr content from 3 to
25 % have been studied using isothermal mechanical spectroscopy. The Zener relaxation caused by
reorientation of pairs of substitute atoms in Fe is observed in all studied alloys and used to evaluate
the activation parameters of Al (Cr) atom jumps in Fe. The second internal friction peak at higher
temperatures was observed only in Cr containing alloys. Isothermal mechanical spectroscopy
(employed frequency from 10-4 to 102 Hz) gives some advantages as compared with ordinary
techniques, i.e. study of anelasticity as a function of temperature. It allows to avoid transient effects
and to measure materials in a state close to equilibrium. This allows to distinguish clearly between
Al atom diffusion in Fe3Al in B2 and D03 states (activation energies for Fe – 26 Al in the B2 range
the HB2 ≈ 235 kJ/mol, and in the D03 ordered range the HD03 ≈ 286 kJ/mol). Effect of chromium on
the Zener relaxation is analysed.
Passive State Degradation of Stainless Steel Welds
Authors: Číhal Vladimír , Blahetová Marie , Krhutová Zdenka , Lasek Stanislav , Kalabisová E.
Published: March 2009

Three types of corrosion attack frequently suffered by type Cr18Ni10 stainless steel in the
heat-affected zone of welds were studied – knife-line, fusion-line, and fissure corrosion. Possible
mechanisms and selected preventative measures were discussed in the light of microstructural
findings.
The Analytical and Computational Thermodynamics of Closed Binary Systems
Authors: Udovsky A.L.
Published: March 2009

The Review. The presented results got by author in the field of analytical and computing thermodynamics of the binary systems for the last 25 years. This review includes following sections. In the first section, transition from description of the equilibrium of the phases in two-phase open binary system to description of the equilibrium of the phases in two-phase closed binary system is shown. It allows to go from problem of global minimization in five-dimension space with provision for restrictions to problem of searching for of the global minimum in 3-dimension space with provision for restrictions. The derivation of the system of equations for equilibrium of two phases in closed binary system is given in the second. The third section, different interpretations (as physical, for as geometric and chemical) for the set of the equations for two phases equilibrium for closed binary system are discussed. Analytical description of invariance for the set of equations of phase equilibrium at transformation of molar Gibbs free energies relatively algebra adding of linear functions on compositions with coefficients, which are any functions of temperature and pressure, is proved in the fourth section. The generalization of the Maxwell’s rule in conjugate coordinates for closed binary systems, which is given the fifth section, has allowed to formulate the new algorithm (U-algorithm) of the calculation of the phase diagrams. The autonomous U-algorithm unlike Newton-method (and its modifications), which is describes in the sixth section, does not require the tasks of the initial approach and possesses the square-law velocity to convergence as Newton - method. Some applications of computer programs, which bases on the U-algorithm, for calculated binary phase diagrams, including solution of indirect problems, are described in the seventh section In the eight section obtained results with comparison published papers are discussed. Finally, in the ninth section, we summarize and discuss in short form of some open problems at present and on which are received only first results.
Statistical Thermodynamics and Ordering Kinetics of D019-Type Phase: Application of the Models for H.C.P.-Ti–Al Alloy
Authors: Radchenko Taras M. , Tatarenko Valentin A. , Zapolsky Helena
Published: March 2009

Using the self-consistent field approximation, the static concentration waves approach and the Onsager-type kinetics equations, the descriptions of both the statistical thermodynamics and the kinetics of an atomic ordering of D019 phase are developed and applied for h.c.p.-Ti–Al alloy. The model of order–disorder phase transformation describes the phase transformation of h.c.p. solid solution into the D019 phase. Interatomic-interaction parameters are estimated for both approximations: one supposes temperature-independent interatomic-interaction parameters, while the other one includes the temperature dependence of interchange energies for Ti–Al alloy. The partial Ti–Al phase diagrams (equilibrium compositions of the coexistent ordered α2-phase and disordered α-phase) are evaluated for both cases. The equation for the time dependence of D019- type long-range order (LRO) parameter is analyzed. The curves (showing the LRO parameter evolution) are obtained numerically for both temperature-independent interaction energies and temperature-dependent ones. Temperature dependence of the interatomic-interaction energies accelerates the LRO relaxation and diminishes a spread of the values of instantaneous and equilibrium LRO parameters versus the temperature. Both statistical-thermodynamics and kinetics results show that equilibrium LRO parameter for a non-stoichiometry (where an atomic fraction of alloying component is more than 0.25) can be higher than for a stoichiometry at high temperatures. The experimental phase diagram confirms the predicted (ordered or disordered) states for h.c.p.-Ti– Al.
Solid-State Transformations in Metal Iodides
Authors: Hansen Steve C. , Kobertz D.
Published: March 2009

Numerous solid-state transformations occur in metal iodides. These transformations can be classified into three categories: polymorphic transformations, polytypic transitions and molecular solids. Many of the modifications of metal iodides involve metastable phases transforming into stable phases. Revisions to the In-I and Th-I phase diagrams are made based on data found in the literature.
Study of Phase Transitions by Transient Methods
Authors: Kubičár L. , Vretenár V. , Boháč V.
Published: March 2009

The present paper deals with the application of the transient techniques for thermophysical analysis of the structural changes in materials. The technique has been applied for study of equilibrium transitions as well as for kinetic transitions. A special methodology has been developed to study kinetic transitions like crystallization, melting, etc. in a “pseudo-equilibrium states” by the help of porous structures. The paper includes three different issues: the transient methods for measuring thermodynamic and transport parameters, data analysis and application of the pulse transient method for measurements of materials in thermodynamic equilibrium, pseudoequilibrium and in non-equilibrium (quasi-equilibrium) states. Equilibrium transitions in CsPbCl3 and CsPbBr3 single crystals, kinetic transitions of freezing and thawing water in porous stones and non-equilibriums states in E-glass and Al2O3 ceramics during sintering have been studied.
Those Properties of CMAs We Know Something About
Authors: Fournée V. , Barthés-Labrousse Marie Geneviève , Dubois Jean Marie
Published: March 2009

New tools are nowadays available to solve the crystallographic structure of complex compounds in metallic alloy systems and a vivid interest manifests itself to discover new compounds in multi-constituent alloys with hundreds or more atoms per unit cell. Meanwhile, it is observed that the metallic character of the alloy progressively disappears with increasing the number of atoms in the unit cell. This contribution focuses at a few examples of this atypical behavior of complex metallic alloys, including quasicrystals as the ultimate state of structural complexity in a crystal made of metals. Emphasis is put on surface properties.
On Specific Phase Transitions to the Compound-Like Impurity Nanosegregation Structures at Dislocations and Grain Boundaries in Metals and their Influence on Diffusion-Assisted Processes
Authors: Nechaev Yuriy S.
Published: March 2009

Specific phase transitions to the compound-like impurity nanosegregation structures at dislocations and grain boundaries in metals and their influence on diffusion-assisted processes are considered, mainly, on the basis of the thermodynamic analysis of the related experimental data. The following systems and aspects are in detail considered: (1) the hydride-like nanosegregation of hydrogen at dislocations and grain boundaries in palladium and their influence on the apparent characteristics of hydrogen solubility and diffusivity in palladium; (2) the physics of the anomalous characteristics of diffusion of Fe and other transition impurities in crystalline Al at elevated temperatures, the role of the compound-like nanosegregation (CLNS) of Fe and the others at dislocations and grain boundaries in Al, analysis of the Mössbauer and diffusion data on CLNS of Fe at grain boundaries and dislocations in Al; (3) some new physical aspects of internal oxidation and nitridation of metals (for Cu-0.3%Fe alloy/Cu2O surface layer, and for (Ni-5%Cr) alloy / N2 gas), the role of the compound-like impurity nanosegregation at dislocations and grain boundaries, study results on the deviations from the classical theories predictions and their interpretation. The possibility is considered of nanotechnology applications of the study results for creation of nanostructured metals with compound-like nanosegregation structures at grain boundaries, in order to obtain specific physical and mechanical properties of such a cellural-type nanocomposites. In particular, it can be complex hydride-like, carbide-like, nitride-like, carbide-nitride-like, oxide-like or intermetallide-like nanosegregation structures at grain boundaries of nanostructured metals.
Molecular-Dynamics Analysis of the Structural Properties of Silica during Cooling
Authors: Lee Byoung Min , Munetoh Shinji , Motooka Teruaki , Yun Yeo Wan , Lee Kyu Mann
Published: March 2009

The structural properties of SiO2 liquid during cooling have been investigated by
molecular dynamics simulations. The interatomic forces acting on the particles are calculated by the
modified Tersoff potential parameters. The glass transition temperature and structural properties of
the resulting SiO2 system at various temperatures have been investigated. The fivefold
coordinations of Si and threefold coordinations of O atoms were observed, and the coordination
defects of system decrease with decreasing temperature up to 17 % at 300 K. The self-diffusion
coefficients for Si and O atoms drop to almost zero below 3000 K. The structures were distorted at
high temperatures, but very stable atomic network persisted up to high temperature in the liquid
state.
Reaction Rate as an Effective Tool for Analysis of Chemical Diffusion in Solids
Authors: Sinder Micha , Burshtein Z. , Pelleg Joshua
Published: March 2009

In their paper, R. Merkle et al [R. Merkle, J. Maier, K.D. Becker and M. Kreye, Phys.
Chem. Chem. Phys. 6, 3633 (2004)] conducted an experimental study on the chemical diffusion of
oxygen in Fe-doped SrTiO3 single crystals driven by large changes in the oxygen ambient partial
pressure. The stoichiometry dependence of the chemical diffusion coefficient was derived on the
basis of the concept of conservative ensembles for two independent trapping reactions, which then
served for calculating the evolution of vacancy profiles. The theoretical predictions were compared
to the experimental results. In the framework of the same model, in the present communication, the
chemical diffusion of oxygen was analyzed by the concept of a dynamic reaction front [M. Sinder,
J. Pelleg, Phys. Rev. E 61, 4935 (2000); Z. Koza, Phys. Rev. E 66, 011103 (2002)]. We show, that
by using a quasi-chemical reaction rate profile, it is possible to obtain information relating to the
position and width of the zone where the reaction takes place. It is indicated, that the reaction rate
distribution can be directly calculated from measured concentration profiles of the immobile
reactant.
Atomic Scale Modelling of Materials: A Prerequisite for any Multi-Scale Approach to Structural and Dynamical Properties
Authors: Matsubara Masahiko , Celino Massimo , Salmon Philip S. , Massobrio Carlo
Published: March 2009

We describe two examples of application focusing on first-principles molecular
dynamics as an effective tool to unravel the atomic-scale structure of condensed-matter systems.
The first application is on disordered network-forming materials and the second is on silicon-doped
fullerenes. We show that an accurate modelling of interatomic forces based on density functional
theory, when combined with an account of the temperature evolution, is an unavoidable prerequisite
for analyzing and interpreting experimental results on a quantitative basis. In the case of disordered
systems, we describe the basic structural features of amorphous GeSe4 and highlight the
predominant chemical order in this system. The effect of adding or removing an electron charge on
the stability of Si-doped fullerenes is exemplified by considering the finite temperature evolution of
heterofullerenes.
First-Principles Calculations of Pd/Au(100) Interfaces with Adsorbates
Authors: Tanaka Shingo , Taguchi Noboru , Akita Tomoki , Hori Fuminobu , Kohyama Masanori
Published: March 2009

Atomic and electronic structures of H-adsorbed Pd overlayers on Au(100) substrates
have been studied by first-principles calculations. The geometric strain effects change the electronic
structure and local reactivity of the surface. The lattice strained Pd overlayers on Au surfaces have
larger adsorption energies for atomic hydrogen than the unstrained Pd slabs. Adsorption energies
for several adsorption sites on the models with different numbers of Pd overlayers have been
analyzed from the viewpoints of strains and H-Pd and H-substrate interactions.
Blue Laser Diodes by Low Temperature Plasma Assisted MBE
Authors: Skierbiszewski Czeslaw
Published: March 2009

Recent progress in the growth of nitride based semiconductor structures made by plasma
assisted MBE (PAMBE) is reported. The technology is ammonia free and the nitrogen for growth is
activated by an RF plasma source from nitrogen molecules. A new approach for the growth of
nitrides by PAMBE at temperature range 500 - 600°C is described. The key for this technique is to
use a thin, dynamically stable metal (In or Ga) layer on the (0001) GaN surface, which enables a
high quality 2D step-flow growth mode to be achieved at temperatures much lower than those
determined by thermodynamic considerations. A new perspective for PAMBE in optoelectronics
has been opened recently by a demonstration of continuous wave operation of InGaN blue–violet
laser diodes. These laser diodes were fabricated on bulk GaN substrates with a low threading
dislocation density.
Nanostructure Formation in Austenitic Stainless Steel
Authors: Krawczynska Agnieszka T. , Lewandowska Małgorzata , Kurzydlowski Krzysztof Jan
Published: March 2009

Samples of 316LVM stainless steels were hydrostatically extruded in a multi-step
process to a total true strain of 1,84 and subsequently annealed at different temperatures. The
structural changes occurring as a result of HE and annealing were observed using a transmission
electron microscope. The microhardness of the samples was measured using a load of 200g.
The results show that hydrostatic extrusion results in a uniform microstructure characterized by a
high density of nano-twins. Subsequent annealing at 600°C produces a partial transformation to a
nano structure of average grain size 54 nm. At an annealing temperature of 700°C a fullyrecrystallized
uniform microstructure consisting of 68 nm diameter nano-grains was formed. It
should be noted that 700°C is much lower than that required to recrystallize a micro-grained alloy
of the same composition. The microstructural changes which occurred during annealing have a
significant effect on the mechanical properties. The microhardness after HE increased following
annealing at 500°C. However, annealing at 800°C resulted in a drop in microhardness, indicating
the occurrence of grain growth.
Nanoscale Nickel-Free Austenitic Stainless Steel
Authors: Tulinski Maciej , Jurczyk Karolina , Jurczyk Mieczyslaw
Published: March 2009

In this work Ni-free austenitic stainless steels with nanostructure were synthesized by
mechanical alloying (MA), heat treatment and nitrogenation of elemental Fe, Cr, Mn and Mo
microcrystalline powders. The phase transformation from ferritic to austenitic was confirmed by
XRD analysis. The mechanical and corrosion properties of the produced biomaterials were
investigated. Additionally, the biocompatibility of nickel-free austenitic stainless steels with
nanostructure and microcrystalline 316L steel, were analyzed studying the behaviour of Normal
Human Osteoblast (NHOst) cells from Cambrex (CC-2538). An enhancement of the properties due
to the nanoscale structures in the bulk consolidated materials was observed.
Mesoporous Crystals of Transition Metal Oxides
Authors: Zhou Wu Zong
Published: March 2009

Using mesoporous silicas as hard templates and facilitating crystal growth of transition
metal oxides inside the pores, some mesoporous crystals can be produced after removing the
templates. This paper gives a brief review of the research of mesoporous crystals of transition
metal oxides in the last five years, including the technical development and potential applications of
the new form of oxides.
Semi-Solid Metal Processing – A Process Looking for a Market
Authors: Kapranos Plato
Published: March 2009

The birth of Semi-Solid Metal Forming (SSM) or as it has now come to be widely known,
Thixoforming, is a typical case of development of a technological innovation. Serendipity, stroke of
luck, call it what you may, the beginning of SSM is based on an almost accidental discovery by a
student carrying out a series of meticulous experiments.
On the one hand, some technological failures have contributed to the lack of success across the board
for SSM technologies. On the other hand, the ‘long childhood’ of the resulting technology or the
process of moving from ‘Innovative Idea to Market' has been largely the result of difficult and in
hindsight sometimes wrong managerial decisions, occasional personality clashes, patent rights and at
times unavoidable all out business 'warfare'. Of course, hindsight is beautiful but unfortunately it
always comes after the event. However, if one looks carefully at some of the notable successes of
SSM forming one can discern that the problems were more on the human scale; people failures rather
than technology failures.
This paper aims to bring out some of these points by outlining the historical development of
Thixoforming.
One-Step SSM Process by MSC & HPDC for Metallic Components
Authors: Martínez Hader V. , Valencia M.F. , Morales Alejandro , Duque Andres F. , Arroyave Mauricio , Cruz J.
Published: March 2009

The preliminary experimental results on microstructure evolution and simulation of an
alternative semisolid route to manufacture near-net shape components are reported. The rheocasting
for semi-solid alloys was first performed by conventional mechanical stircasting (MSC), followed
by direct shaping of the SSM slurry into a high-pressure die-casting machine (HPDC), thus
avoiding the storage and reheated to the semisolid state of the ingots prior the shaping process.
To assure high quality for the semisolid slurry, the microstructural evolution was characterized by
digital image analyses. The HPDC process of a simple part, simulated using CFD tools (Flow-3D®-
Flow Science Inc.) is also reported. By means of such simulation the integrity of shaping
components was studied.