bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous Solid Solution of -K-phase in the Third Period Transition Metals-Aluminum-Carbon Pseudo-Ternary Systems
Authors: Hosoda Hideki , Suzuki Kensyo , Hanada Shuji 
Published: April 2011

ABSTRACTPhase stability of κ-phases (perovskite-type phases) was studied in the third-period transitionmetals (M: Mn to Cu) - aluminum (Al) - carbon (C) systems. The concentrations of transition metals (CM) were systematically changed from 60mol%Mn to 20mol%Ni+40mol%Cu along the periodic table under the constant nominal alloy compositions of CMl+CM2=60mol%, CA1=60mol% and Cc=20mol%. Alloys were prepared using mechanical alloying and hot pressing. Constituent phases were investigated by X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. It is confirmed that Mn3Al(C,O)0,95, Fe3Al(C,O)0.87, Co3AI(C,O)0. 6 and Ni3Al(CO)0.26 exist in their ternary systems where oxygen is introduced during the process. Also, only one κ-phase is recognized in an alloy having an intermediate composition in every system. This suggests that continuous solid solutions between these κ-phases are formed in the pseudo-ternary systems. Composition dependence of lattice parameter is discussed.
Mechanical Properties of E21 (Mn, Fe)3AIC-Base Alloys
Authors: Suzuki Kensyo , Hosoda Hideki , Hanada Shuji 
Published: April 2011

ABSTRACTMechanical properties of E21 (Mn, Fe)3AlC-base alloys were investigated. The E21 crystal structure is closely related to L12, and thereby E21 compounds are expected to exhibit superior properties similar to those of the L12 Ni3AL. Nominal compositions are fixed to be 60mol%(Mn, Fe)-20mol%A1–20mol%C. Alloys were prepared by mechanical alloying and hot pressing. ICP chemical analysis, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis were carried out for alloy characterization. Mechanical properties were evaluated by Vickers hardness tests at room temperature (RT) and compression tests from RT to 1273K. Strain rate dip tests were also carried out. It is found that most alloys are composed of two phases of E21 as the primary phase and graphite as the precipitates, and that the volume fraction of graphite increases with increasing Fe content. Hardness and 0.2% flow stress at RT are raised with increasing Fe content. At RT, 0.2% flow stress and fracture strength of Fe3A1C alloy used are 2.9GPa and 3.4GPa, respectively. An alloy containing 40%Mn-20%Fe shows weak positive temperature dependence of strength at 700–800K, similar to the observation in some Co3AIC alloys. Moreover, work-hardening coefficient of all alloys shows strong positive temperature dependence below 700K. These results suggest the occurrence of K-W related mechanism for plastic deformation in these alloys.
Thermal Fatigue of NiAl Single Crystals
Authors: Kush M. T. , Holmes J. W. , Gibala R. 
Published: April 2011

ABSTRACTSingle crystals of [001]-oriented NiAI single crystals were subjected to thermal fatigue by a method which employs induction heating of disk-shaped specimens heated in an argon atmosphere. Several time-temperature heating and cooling profiles were used to produce different thermal strain histories in specimens cycled between 973 K and 1473 K. After thermal cycling, pronounced shape changes in the form of diametrical elongations along <100> directions with accompanying increases in thickness at and near the <100> specimen axes were observed. The deformations were analyzed in terms of operative slip systems in tension and compression, ratchetting (cyclic strain accumulation), and the elastic properties of NiAl. The experimental results correlate best with thermal stresses associated with the large elastic anisotropy of NiAl.
Fabrication Of High Quality Qc Films Via The Route Of The Amorphous Phase
Authors: Haberkern R. , Roth C. , Knöfler R. , Schulze L. , Häussler P. 
Published: April 2011

AbstractWe discuss the preparation of thin icosahedral films (Al-Cu-Fe and Al-Pd-Re) via the route of the amorphous (a-)phase which in some aspects is a precursor to the icosahedral phase. A direct transition from the a- to the i-phase occurs for Al-Cu-Fe films at 430°C on the time scale of minutes. The resulting films are of good quality as shown by diffraction and electronic transport properties. The surface of the resulting films is very smooth.
Structural Studies Of Decagonal Quasicrystals And Approximants Using The High-Angle Annular Dark-Field Method
Authors: Saitoh Koh , Tsuda Kenji , Tanaka Michiyoshi , Tsai An Pang 
Published: April 2011

AbstractHigh-angle annular dark-field (HAADF) images of an A172Ni20Co8 decagonal quasicrystal and monoclinic Al13Fe4 and τ2-inflated Al13C04 approximants have been presented. We found that a 2 nm atom cluster of Al72Ni20Co8, which have been believed to be tenfold so far, has no tenfold symmetry. A new structural model of Al72Ni20Co8 has been constructed on the basis of the HAADF images and the structure of monoclinic Al13Fe4 approximant. We have found that the monoclinic Al13Fe4 and τ-inflated Al13Co4 approximants are composed of the same basic structure of a pentagonal atom cluster with an edge length of 0.47 nm. We have also found that a fivefold atom-cluster with a 2 nm diameter exists in τ-Al13Co4, which was observed in decagonal quasicrystals of Al-Ni-Fe, Al-Ni-Co, Al-Cu-Co and Al-Co by highresolution electron microscopy. A structural model of τ-inflated Al13Co4 is constructed on the basis of the convergent-beam electron diffraction symmetry, HAADF images and the structure of monoclinic Al13Fe4.
Characterization And Properties Of The AIPdMn 5 Surface
Authors: Cappello G. , Dechelette A. , Schmithusen F. , Chevrier J. , Comin F. , Stierle A. , Formoso V. , De Boissieu M. , Lograsso T. , Jenks C. , Delaney D 
Published: April 2011

AbstractThe surface of the AlPdMn quasicrystal perpendicular to a fivefold axis has been probed by LEED, XPS, Auger spectroscopy and surface EXAFS.
Oxidation Of AI-Cu-Fe Quasicrystals
Authors: Wehner B. I. , Köster U. 
Published: April 2011

AbstractThe oxidation behavior of i-A163Cu25Fe12 at 800°C in air was investigated by means of TGA, XRD, SEM and TEM. In the beginning a homogeneous oxide layer is formed by the subsequent growth of metastable γ-Al2O3 and Θ-Al2O3. Nucleation of the thermodynamical stable α-Al2O3 occurs at the interface oxide/quasicrystal. The following growth of α-Al2O3 through the oxide layer leads to the formation of oxide nodules. The high growth rate of the α-Al2O3 can be explained by the incorporation of copper ions. The oxidation resistance of the quasicrystal is insufficient at high temperatures, because no protective oxide layer is formed. The high temperature oxidation behavior of Al-Cu-Fe quasicrystal and the aluminides β-FeAl and β-NiAl is compared regarding the oxidation rate, the oxide phases and the concentration changes in the material due to selective oxidation of aluminum.
Effect of Processing Variables on The Magnetic Field Orientation of Liquid Crystalline Thermosets
Authors: Lincoln Derek M. , Douglas Elliot P. 
Published: April 2011

ABSTRACTWe have investigated the effect of various processing variables on the magnetic field orientation of a liquid crystalline epoxy. By using a modified fractional factorial design, we created an empirical model which can be used to predict the degree of orientation as a function of these variables. The model predicts the correct qualitative trends, namely that orientation increases with increasing magnetic field strength, increases with increasing time in the field, and decreases with increasing B-staging. The model also reveals some surprising effects of B-staging on the degree of orientation.
The Dynamic Properites of Confined Antiferroelectric Liquid Crystal Investigated By Photon Correlation Spectroscopy
Authors: Panarin Yu.P. , Rosenblatr C. , Aliev F.M. 
Published: April 2011

ABSTRACTDynamic light scattering was used to examine ferrielectric liquid crystalline phases in porous media. Whereas in larger pores (200 Å) ferrielectric phases were observed, they were not found in the smallest pores (200 Å). Additionally, the temperatures of SmC - SmA phase transition were found to be suppressed in the pores relative to bulk, while SmCA - SmCγ phase transition is not affected by the confinement. These observations have been explained by the structural aspects of antiferroelectric liquid crystalline materials in a confined geometry and show the importance of long range electrostatic interaction for existence of ferrielectric phases.
Polymer Dispersed Liquid Crystals as Optical Storage Materials
Authors: Simoni F. , Bella S. Di , Lucchetti L. , Cipparrone G. , Mazzulla A. 
Published: April 2011

ABSTRACTAmong the different methods used to prepare Polymer Dispersed Liquid Crystals (PDLC), the Polymerisation Induced Phase Separation technique (PIPS) can be exploited to obtain optical recording in these materials. The possibility of performing optical storage of binary images in PDLC during the curing process and post curing holographic recording, will be described and discussed.
Grazing Incidence X-Ray Scattering Studies of the Structure and Morphology of the Ni/Mgo(001), Co/Nio(111) and Nife/Nio(111) Interfaces During their in Situ Growth
Authors: Renaud G. , Barbier A. , Mocuta C. 
Published: April 2011

ABSTRACTCombined in situ structural and ex situ magnetic studies of the Co/NiO(111) and Ni81Fe19/NiO(111) interfaces are presented. The Co and Permalloy films were grown on NiO(111) single crystals. Structural studies were performed by Grazing Incidence X-ray Scattering during growth. The effect of the temperature of the substrate during deposition was investigated. Under specific growth conditions, almost pure FCC Co and NiFe films can be obtained, with small quantities of twins. Magnetic measurements were performed ex situ by Magneto-Optical Kerr Effect (MOKE). A strong correlation between the magnetic properties and the crystallographic structure of the Co film is evidenced. High coercive fields are measured for all samples. High temperature annealing of the NiFe film leads to an improved crystalline quality, but the interface becomes reactive and diffuse: part of the Fe diffuses into the NiO substrate and forms an interface compound, likely to be the spinel NiFe2O4. We also report an in situ grazing incidence X-ray scattering study of the Ni/MgO(001) interface during its formation at room temperature. In-plane measurements reveal that the interface is sharp and that the epitaxial relationship is complex. Two distinct lattices are found to exist: expanded Ni(001) and Ni(110). The latter exhibits several orientations with respect to the substrate depending on the thickness. The Ni(110) orientations disappear by annealing at high temperature, leaving only the Ni cube/cube orientation. The layer was also almost fully transformed into NiO(001) by high temperature oxidation.
Growth and Structure of Metallic Barrier Layer and Interconnect Films I: Exeriments
Authors: Windt D. L. , Tortre J. Dalla , Gilmer G. H. , Sapjeta J. , Kalyanaraman R. , Baumann F. H. , O'Sullivan P. L. , Dunn D. , Hull R 
Published: April 2011

ABSTRACTWe present experimental results directed at understanding the growth and structure of metallic barrier layer and interconnect films. Numerical simulation results associated with this experimental work are presented in an accompanying paper in these proceedings. Here, thin films of Al, Ti, Cu and Ta have been grown by magnetron sputtering onto oxidized Si substrates. Using a specially-constructed substrate holder, the orientation of the substrate with respect to the growth direction was varied from horizontal to vertical. Films were grown at both low and high argon pressure; in the case of Ta, the cathode power was varied as well. The film structure and in particular the surface roughness was measured by X-ray reflectance and also by atomic force microscopy. We find that the surface roughness increases markedly with orientation angle in the case of Ta and Cu films, and in Ti films grown at high argon pressure. At low pressure, however, the Ti film surface roughness remains constant for all substrate orientations. No variation in roughness with either orientation angle or argon pressure was observed in the Al films. These results suggest that, under certain circumstances, shadowing effects and/or grain orientation (i.e., texture) competition during growth can give rise to lower density, more porous (and thus more rough) films, particularly at large orientation angles, as on sidewalls in sub-micron trenches.
Crystalline Texture of CoCrPt Films on CrMn/NiAl and Cr/NiAl Underlayer Structures
Authors: Zou J. , Lu B. , Bayer A. E. , Laughlin D. E. , Lambeth D. N. 
Published: April 2011

ABSTRACTIn this study, we examine the effects of CrMn/NiAl and Cr/NiA1 underlayer structures on the crystalline texture and microstructure of CoCrPt magnetic films using x-ray and electron diffraction. The former underlayer structure was found to induce better CoCrPt (image1) texture. The stress in the CoCrPt layer was measured. The effective in-plane anisotropy energy densities of the CoCrPt films on the above two underlayers were also measured by using out-of-plane torque and Miyajima methods and the result was consistent with the texture analysis.
Microstructural Characterization Methods for Magnetic Thin Films
Authors: Wittig J. E. , Bentley J. , Nolan T. P. 
Published: April 2011

ABSTRACTMicrostructural characterization is key to determining the structure-property-processing relationships required to optimize the performance of magnetic thin films for longitudinal magnetic recording. Since the grain size of modem recording media is on the order of 10 to 20 nm, only high-resolution characterization methods such as transmission electron microscopy (TEM) can accurately describe the microstructure. Complete analysis requires a combination of conventional and high-resolution TEM imaging with analytical methods such as energy dispersivespectroscopy and energy-filtered TEM imaging. This paper provides examples from CoCr(Pt,Ta) alloys that reveal the strengths and limitations of these characterization methods as they apply to microstructural characterization of magnetic thin films.
N2O Oxidation Kinetics of Ultra Thin Thermally Grown Silicon Nitride: An Angle Resolved X-Ray Photoelectron Spectroscopy Study
Authors: Mao A. Y. , Lozano J. , White J. M. , Kwong D. L. 
Published: April 2011

ABSTRACTThe oxidation kinetics of ultra thin thermally NH3-nitrided Si3N4 films in N2O ambient has been extensively studied using angle resolved x-ray photoelectron spectroscopy (ARXPS). Ultra thin (7Å) Si3N4 films formed by RTP nitridation of Si in NH3 were annealed in N2O at various temperatures (700 °C - 1000 °C) for 30 sec. ARXPS showed that Si substrate at the Si-Si3N4 interface was oxidized when annealed at 1000 °C for 30 sec, and was accompanied by the oxidation of the top Si3N4 surface. The total film thickness increases 4–5 times of that of the original Si3N4 layer. However, the oxide formed on the top Si3N4 surface is twice as thick as that formed at the Si3N4/Si interface. No interfacial oxide was found when annealing below 900°C, although the formation of the silicon oxide and oxynitride above the Si3N4 layer was still observed.
Nitridation by NO Or N2O of Si-SiO2 Interfaces
Authors: Caricato A. P. , Cazzaniga F. , Cerofolini G. F. , Crivelli B. , Polignano M. L. , Tallarida G. , Valeri S. , Zonca R. 
Published: April 2011

ABSTRACTX-ray photoelectron spectroscopy (XPS) and photocurrent measurements for the determination of surface recombination velocity provide complementary information on the structure of the Si-SiO2 interface, being sensitive to the chemical nature of foreign species at the interface the former, and to intrinsic defects the latter. The comparison of the XPS N(1s) peaks determined for the Si-Si0 2 interfaces nitrided in NO or N2O ambients is useful to identify the species responsible for the broadening of the peak. In fact, nitridation by NO is mainly responsible for the formation of Si3N moieties at the silicon surface in which silicon atoms are partially oxidized; while nitridation by N2O proceeds with the oxidation of Si – Si backbonds to Si – N bonds, thus resulting in the formation of N(Si(O-)3)3 groups embedded in the oxide. Surface recombination velocity by photocurrent measurements gives evidence that nitridation in N2O is associated with an appreciable co-oxidation, while nitridation in NO is mainly associated with the passivation of interface states. Furthermore N2O and NO nitridation are responsible for different morphologies of the nitrided layers.
Nitrogen Profile Engineering for Tunnel Oxynitrides
Authors: Sugizaki Taro , Tada Yoko , Hikazutani Ken-Ichi , Nakanishi Toshiro , Takasaki Kanetake 
Published: April 2011

ABSTRACTWe consider nitrogen profiling in oxynitrides to be the key technology for next generation Flash Memories, because of its ability to suppress the generation of traps in tunnel oxides. We are trying to develop an oxynitriding technique for tunnel oxides that uses nitric monooxide. This time, we tried to control nitrogen profile in oxynitrides by using reoxidized oxynitride process. By using a three- step oxidationoxynitridation-reoxidation process, we attempted to systematically tune oxidation conditions, to obtain a satisfactory tunnel oxide/Si interface and SILC characteristics. Highly reliable tunnel oxide for flash memory has been achieved using recently developed reoxidized oxynitrides processing, which is characterized by wet oxidationoxynitridation-dry oxidation. This process yields excellent characteristics, such as low oxide trap formation, low leakage current, and high charge to breakdown (Qbd). This three-step oxynitride process is best suited for flash memories having superior Program/Erase (P/E) cycling endurance and data retention characteristics. In addition, I will propose the optimum conditions for the reoxidation process.
Ultrathin oxide film formation using radical oxygen in a UHV system
Authors: Watanabe K. , Kimura S. , Tatsumi T. 
Published: April 2011

ABSTRACTRadical oxidation at thickness of under 2.0 nm in an ultrahigh vacuum (UHV) system with an electron cyclotron resonance (ECR) plasma has been studied. The interface roughness and oxide density were evaluated by atomic force microscopy (AFM) and grazing incidence xray reflectrometry, respectively. We found the oxide thickness could be easily controlled at Tsub = 750°C when using radical oxygen at 5.0×10−3Torr. The interface roughness at a thickness of 1.8 nm, measured by the root mean square (RMS), was 0.11 nm. The density of the radical oxide fell as the oxide thickness decreased, especially at less than 2.0 nm. However, the density of the radical oxide annealed in molecular oxygen at 5×10−3Torr and Tsub = 750°C increased, without the oxide thickness increasing. We think that the first insertion of an oxygen atom into the first Si layer has a much higher energy barrier than that into a SiOx layer. The radical oxygen can pass through this higher energy barrier, and thus oxygen molecules fill the oxide layers. This mechanism means that we can control the oxide thickness and density separately at thickness of less than 2.0 nm through the radical oxidation time and the annealing time in molecular oxygen. We expect low-pressure radical oxidation to be the most suitable process for future ultrathin gate oxidation.
Tantalum Pentoxide Gate Dielectrics Formed by Tantalum Oxidation
Authors: Hobbs C. , Hegde R. , Maiti B. , Nagabushnam R. , La L. , Reid K. , Dip A. , Grove L. , Conner J. , Kaushik V. , Prabhu L. , Anderson A. , Bagchi S. , Mendonca J. , Tobin P. 
Published: April 2011

ABSTRACTTantalum pentoxide (Ta2O5) films were formed by oxidizing thin tantalum (Ta) films on bare and NO-nitrided silicon substrates. The 43-400 Å thick Ta films were deposited using physical vapor deposition (PVD) and oxidized using O2 for 2-60 min at 550-800 C in a furnace or single wafer tool. Uniform and stoichiometric Ta2O5 films were successfully produced as determined from XRD, AES depth profiling, XTEM, and ellipsometric analysis. The nitridation pretreatment was found to minimize the interfacial Ta-Si reactions which occur during the oxidation. Well-behaved CV and IV curves were obtained from mercury probe measurements. No CV hysteresis was observed. An equivalent oxide thickness of 38 Å and a leakage current of 7×10−9 A/cm2 at +1V were obtained for a 120 Å thick Ta2O5 film on a 15 Å interfacial SiO2 layer.
Properties of Epitaxial SrTiO3 Thin Films Grown on Silicon by Molecular Beam Epitaxy
Authors: Yu Z. , Droopad R. , Ramdani J. , Curless J.A. , Overgaard C.D. , Finder J.M. , Eisenbeiser K.W. , Wang J. , Hallmark J.A. , Ooms W.J. 
Published: April 2011

ABSTRACTSingle crystalline perovskite oxides such as SrTiO3 (STO) are highly desirable for future generation ULSI applications. Over the past three decades, development of crystalline oxides on silicon has been a great technological challenge as an amorphous silicon oxide layer forms readily on the Si surface when exposed to oxygen preventing the intended oxide heteroepitaxy on Si substrate. Recently, we have successfully grown epitaxial STO thin films on Si(001) surface by using molecular beam epitaxy (MBE) method. Properties of the STO films on Si have been characterized using a variety of techniques including in-situ reflection high energy electron diffraction (RHEED), ex-situ X-ray diffraction (XRD), spectroscopic ellipsometry (SE), Auger electron spectroscopy (AES) and atomic force microscopy (AFM). The STO films grown on Si(001) substrate show bright and streaky RHEED patterns indicating coherent two-dimensional epitaxial oxide film growth with its unit cell rotated 450 with respect to the underlying Si unit cell. RHEED and XRD data confirm the single crystalline nature and (001) orientation of the STO films. An X-ray pole figure indicates the in-plane orientation relationship as STO[100]//Si[110] and STO(001)// Si(001). The STO surface is atomically smooth with AFM rms roughness of 1.2 AÅ. The leakage current density is measured to be in the low 10−9 A/cm2 range at 1 V, after a brief post-growth anneal in O2. An interface state density Dit = 4.6 × 1011 eV−1 cm−2 is inferred from the high-frequency and quasi-static C-V characteristics. The effective oxide thickness for a 200 Å STO film is around 30 Å and is not sensitive to post-growth anneal in O2 at 500-700°C. These STO films are also robust against forming gas anneal. Finally, STO MOSFET structures have been fabricated and tested. An extrinsic carrier mobility value of 66 cm2 V−11 s−1 is obtained for an STO PMOS device with a 2 μm effective gate length.
Electrical Characterization of Al2O3 - SiO2 Mos Structures
Authors: Ragnarsson L-Å , Aderstedt E. , Lundgren P. 
Published: April 2011

ABSTRACTA comparative capacitance voltage method is used to investigate the equivalent thickness reduction during post metallization annealing of thermally grown ultrathin (∼15-27 Å) oxides. It is found that a double layered dielectric consisting of a thin Al2O3—SiO2 sandwich is appropriate to describe both the increased capacitance and the nearly unaltered current after anneal. It is further shown that the impact of initial thickness and method of growth — in a conventional furnace or by rapid thermal oxidation — on the equivalent thickness reduction is negligible.