A Solid State Amorphisation Reaction in Ti-Si Diffusion Couples: The Phase Field

1987 ◽  
Vol 103 ◽  
Author(s):  
Ivo J. M. M. Raaijmakers ◽  
Piet H. Oosting ◽  
Alec H. Reader
Keyword(s):  
Cross Section ◽  
Phase Field ◽  
Amorphous Layer ◽  
Diffusion Couples ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition Diagram ◽  
Transmission Electron ◽  
Phase Nucleation ◽  
Sputter Deposited

ABSTRACTThe reactions in sputter deposited Si-Ti-Si diffusion couples were investigated with X-ray diffraction, Auger electron spectroscopy and cross-section transmission electron microscopy. Anneals at a temperature of 400°C resulted in the growth of an amorphous phase at the Si-Ti interfaces. Crystalline silicides were only found after an anneal at temperatures of 500°C or higher.It was demonstrated that an amorphous layer of approximately 8 nm thickness sustained a concentration gradient from about 73% Si at the Si side to about 28% Si at the Ti side of the diffusion couple. The measured width of the phase field agreed with the width predicted from a calculated free energy versus composition diagram. Actually the observed phase field was found to be so wide, that it contains the stoichiometry of all equilibrium silicides. The consequences of our results for the explanation of silicide first phase nucleation were discussed.

InAs Quantum Dots Grown on an AlGaAsSb Strain-Relief Buffer

2000 ◽  
Vol 642 ◽  
Author(s):  
A.L. Gray ◽  
L. R. Dawson ◽  
Y. Lin ◽  
A. Stintz ◽  
Y.-C. Xin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cross Section ◽  
Gaas Substrate ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
X Ray Diffraction ◽  
Strain Relief ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Transmission Electron

ABSTRACTAn In(Ga)As-based self-assembled quantum dot laser test structure grown on strain-relief Al0.5Ga0.5As1-ySby strain-relief buffer layers (0≤y ≤ 0.24) on a GaAs substrate is investigated in an effort to increase dot size and therefore extend the emission wavelength over conventional InAs quantum dots on GaAs platforms. Cross-section transmission electron microscopy, and high-resolution x-ray diffraction are used to monitor the dislocation filtering process and morphology in the buffer layers. Results show that the buffer layers act as an efficient dislocation filter by drastically reducing threading dislocations, thus providing a relaxed, low dislocation, compositionally modulated Al0.5Ga0.5Sb0.24As0.76 substrate for large (500Å height x 300Å width) defect -free InAs quantum dots. Photoluminescence shows a ground-state emission of the InAs quantum dots at 1.45 μm.

Growth and Characterization of (012)- and (001)-Oriented Epitaxial Anatase Thin Films

2006 ◽  
Vol 46 ◽  
pp. 146-151
Author(s):  
Andriy Lotnyk ◽  
Stephan Senz ◽  
Dietrich Hesse
Keyword(s):  
Thin Films ◽  
Cross Section ◽  
Single Phase ◽  
Electron Beam Evaporation ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Transmission Electron

Single phase TiO2 thin films of anatase structure have been prepared by reactive electron beam evaporation. Epitaxial (012)- and (001)-oriented anatase films were successfully obtained on (110)- and (100)-oriented SrTiO3 substrates, respectively. X-ray diffraction and cross section transmission electron microscopy investigations revealed a good epitaxial quality of the anatase films grown on the SrTiO3 substrates.

Diffusion-Induced Recrystallization in Nickel/Palladium Multilayers

2011 ◽  
Vol 309-310 ◽  
pp. 195-202 ◽  
Author(s):  
Guido Schmitz ◽  
M. Kasprzak ◽  
D. Baither
Keyword(s):  
Thin Film ◽  
Driving Force ◽  
Lattice Mismatch ◽  
Ideal Strength ◽  
Diffusion Couples ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
Sputter Deposited ◽  
The Ideal

Diffusion-Induced Recrystallization (DIR) is investigated in size mismatched thin film interdiffusion couples. New grains formed in the diffusion zone are characterized by distinctive composition levels which seem to be characteristic to the interdiffusing materials. In this paper, we analyzed sputter-deposited Ni/Pd films. The lattice mismatch and the driving force are varied by pre-alloying one side of the diffusion couples. Recrystallization was detected after heat treatment by transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry. We determined characteristic concentrations from XRD data. Remarkably, the difference between the concentration inside newly formed grains and that of the parent layers remains practically constant, when initial layer concentration is varied. Also, the characteristic compositions are nearly independent of temperature. A thermo-mechanic model has been derived, which demonstrates that the observed concentration differences are such that the stress in front of the moving grain boundary reaches a maximum close to the ideal strength of the host material.

Reaction Kinetics of Sputter-Deposited Ti On SiO2 Substrates during Rapid Thermal Annealing

1989 ◽  
Vol 146 ◽  
Author(s):  
E.J. Yun ◽  
H.G. Chun ◽  
K. Jung ◽  
D.L. Kwong ◽  
S. Lee
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Kinetics Of

ABSTRACTIn this paper, the interactions of sputter-deposited Ti on SiO2 substrates during rapid thermal annealing in nitrogen at 550°C - 900°C for 10 - 60 s have been systematically studied using X-ray diffraction, Auger electron spectroscopy, transmission electron diffraction, TEM & cross-sectional TEM, and sheet resistance measurements.

The origin of an anomalous, low 2θ peak in x-ray diffraction spectra of MoS2 films grown by ion beam assisted deposition

1997 ◽  
Vol 12 (5) ◽  
pp. 1191-1194 ◽  
Author(s):  
D. N. Dunn ◽  
L. E. Seitzman ◽  
I. L. Singer
Keyword(s):  
Cross Section ◽  
Ion Beam ◽  
Diffraction Peak ◽  
X Ray Diffraction ◽  
Bright Field ◽  
X Ray ◽  
Molecular Defects ◽  
Ion Beam Assisted Deposition ◽  
Transmission Electron ◽  
Anomalous Peak

The origin of a previously reported anomalous low 2θ x-ray diffraction peak from MoS2 thin films grown by ion beam assisted deposition was investigated. The anomalous peak, observed in a film grown on Si(100), was removed by ion irradiating the film with 180 keV Ar++ ions to a dose of 1 × 1015 ions/cm2. Microstructures of the two films were investigated using x-ray diffraction and cross-section transmission electron microscopy. Diffraction data and bright-field images indicated that the low 2θ peak was due to a local interplanar expansion of the crystal structure normal to MoS2 basal planes. This expansion was attributed to molecular defects.

Solid State Amorphization in the Interfacial Reactions of Yttrium Thin Films on (111)Si

1993 ◽  
Vol 311 ◽  
Author(s):  
T.T. Lee ◽  
L.L. Chen
Keyword(s):  
Thin Films ◽  
Electron Spectroscopy ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Interfacial Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
State Amorphization ◽  
Amorphous Interlayer

ABSTRACTInterfacial reactions of ultrahigh vacuum deposited yttrium thin films on atomically clean (111)Si at low temperatures have been studied by both conventional and high resolution transmission electron microscopy, Auger electron spectroscopy and x-ray diffraction. A 10–nm–thick yttrium thin film, deposited onto (lll)Si at room temperature, was found to completely intermix with Si to form an 11–nm–thick amorphous interlayer. Crystalline Y5Si3 and Si were observed to nucleate first within the amorphous interlayer in samples annealed at temperatures lower than 200 °C. Epitaxial YSi2−x was found to be the only phase formed at the interface of amorphous interlayer and crystalline Si in samples annealed at temperatures higher than 250 °C. In as deposited 20– to 60–nm thick Y thin films on silicon samples, crystalline Y5Si3, Si, and YSi and a 2.5–nm–thick amorphous layer were found to be present simultaneously.

Structure and Composition of Luminescent Laterally Anodized Porous Si

1991 ◽  
Vol 256 ◽  
Author(s):  
K. H. Jung ◽  
S. Shih ◽  
T. Y. Hsieh ◽  
J. C. Campbell ◽  
D. L. Kwong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lower Layer ◽  
Amorphous Layer ◽  
Porous Si ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
High Concentrations ◽  
Secondary Ion ◽  
Very High

ABSTRACTWe have made structural and compositional studies of luminescent laterally anodized porous Si. Scanning electron microscopy reveals a surface with a network of cracks, while transmission electron microscopy shows a dual porous Si structure in which the upper layer is amorphous and the lower layer is either amorphous or crystalline, depending on anodization conditions. X-ray diffraction verified the presence of the amorphous layer. Secondary ion mass spectroscopy reveals very high concentrations of H, B, C, N, O, and F in the amorphous layer. Our results indirectly suggest that the amorphous layer is primarily responsible for luminescence.

Microstructure and Kinetics of the Interface Reaction Between Titanium Thin Films and (112) Sapphire Substrates

1989 ◽  
Vol 167 ◽  
Author(s):  
J.H. Selverian ◽  
F.S. Ohuchi ◽  
M.R. Notis
Keyword(s):  
Cross Section ◽  
Interface Reaction ◽  
Interfacial Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Titanium Thin Films ◽  
Thickness Measurements ◽  
Kinetics Of

AbstractWe studied the reactivity of titanium with the R-plane (112) surface of sapphire by transmission electron microscopy (TEM), x-ray diffraction (XRD), and Rutherford backscattering (RBS) techniques. Cross-section TEM specimens were prepared from 200–400 nm thick titanium films deposited on sapphire at 25, 525, 554, 562, 580, 630, and 663°C to observe the interfacial region. In samples deposited at 25°C, without further annealing, no reaction zone could be seen in the TEM. In all other samples titanium reduced the sapphire to form Ti0 6 7[O0 3 3] and Ti3Al[O], Ti and Ti3Al with oxygen in solid solution. An activation energy of 24.7 ± 6 kcal/deg-mole was determined for the growth of the Ti3Al[O] layer. Layer thickness measurements from the TEM and RBS studies were within 10–20% of one another.

Structure and Magnetic Properties of FE/ZR Multilayer Films

1993 ◽  
Vol 313 ◽  
Author(s):  
Toyohiko J. Konno ◽  
Takenori Nakayama ◽  
Bruce M. Clemens ◽  
Robert Sinclair
Keyword(s):  
Magnetic Properties ◽  
Amorphous Layer ◽  
Multilayer Films ◽  
Amorphous Structure ◽  
Asymptotic Model ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The One

ABSTRACTWe investigated structural and magnetic properties of Fe/Zr Multilayer films using high-resolution transmission electron Microscopy, X-ray diffraction and vibrating sample Magnetometry. For films with wavelength (Λ) ≥ 80Å, the interface region between the Fe and Zr layers exhibits a 15–20Å thick amorphous structure. The Magnetization curves of these films showed a monotonous decrease in the saturation magnetizations with Λ, whose trend is well explained by a simple asymptotic model that assumes the interface amorphous layer to be non-ferromagnetic. Films with Λ≤40Å exhibit a compositionally-Modulated amorphous structure. The latter films are paramagnetic except for the one with Λ=40Å, which showed a superparamagnetic behavior.

Preparation of SiO2-pillared layered titanate thin films

2000 ◽  
Vol 15 (12) ◽  
pp. 2587-2590 ◽  
Author(s):  
Takeshi Sumida ◽  
Ryu Abe ◽  
Michikazu Hara ◽  
Junko N. Kondo ◽  
Kazunari Domen
Keyword(s):  
Thin Film ◽  
Cross Section ◽  
Photoelectron Spectroscopy ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Layered Titanate ◽  
Cs Ions ◽  
Microscopy Images

The interlayer space of a thin film of layered titanate, Cs0.68Ti1.83‪0.17O4, was successfully expanded by SiO2 pillaring. Ion exchange of the Cs ions in the interlayer to alkylammoniuim cations, n-CnH2n+1NH3+ (n = 8, 12, 18), expanded the interlayer space, and enabled intercalation of tetraethylorthosilicate. X-ray diffraction and the cross section of transmission electron microscopy images revealed that tetraethylorthosilicate-treated thin film maintained the expansion of interlayer space by SiO2 pillaring after calcination at 773 K. X-ray photoelectron spectroscopy after etching the thin film about 100 nm from the surface further confirmed the existence of SiO2 in the interlayer space.

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