Determination of Composition and Linear Lattice Expansion Coefficient in Si1−x Gex/Si Thin Films by Simulation of X-Ray Rocking Curves

1990 ◽  
Vol 208 ◽  
Author(s):  
F. Cembali ◽  
R. Fabbri ◽  
M. Servidori ◽  
A. Zani ◽  
S. Iyer
Keyword(s):  
Thin Films ◽  
Expansion Coefficient ◽  
Molecular Beam ◽  
Depth Distribution ◽  
Waller Factor ◽  
Lattice Expansion ◽  
Linear Lattice ◽  
X Ray ◽  
Debye Waller Factor

ABSTRACTBy simulation of X-ray rocking curves of Si-Ge alloys grown on Si by molecular beam epitaxy and of Ge implanted samples, the Ge composition, the linear lattice expansion coefficient, the strain depth-distribution and the static Debye-Waller factor in the MBE alloys have been determined.

Study on Effects of Heavy Ion Irradiation on CeO2 by Using Synchrotron Radiation X-Ray Absorption Spectroscopy -as a Simulation Study for Radiation Damage in High-Burnup Light Water Reactor Fuels-

2007 ◽  
Vol 1043 ◽  
Author(s):  
Hirotaka Ohno ◽  
Daiju Matsumura ◽  
Yasuo Nishihata ◽  
Jun'ichiro Mizuki ◽  
Norito Ishikawa ◽  
...  
Keyword(s):  
Thin Films ◽  
Synchrotron Radiation ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Waller Factor ◽  
X Ray ◽  
Debye Waller Factor ◽  
Atomic Distance ◽  
Exafs Measurement ◽  
X Ray Absorption

AbstractCeO2 thin films were irradiated with 200MeV Xe ions. Effects of the irradiation were studied by using Extended X-ray Absorption Fine Structure (EXAFS) measurement at SPring8 synchrotron radiation facility. EXAFS spectra for the irradiated thin films near the Ce K-edge show that the coordination number for oxygen atoms around Ce atom decreases and that the Ce-O Debye-Waller factor increases by the irradiation. The atomic distance between oxygen atom and Ce atom does not vary within the accuracy of EXAFS measurement. The effect of high density electronic excitation on the structure of CeO2 is discussed.

scholarly journals Determination of Structure Factors by the Pendellosung Effect for Imperfect Crystals

1988 ◽  
Vol 41 (3) ◽  
pp. 519
Author(s):  
NM Olekhnovich
Keyword(s):  
Tilt Angle ◽  
Oscillation Period ◽  
Waller Factor ◽  
X Ray ◽  
Method Of Determination ◽  
Debye Waller Factor ◽  
Structure Factors ◽  
Integrated Intensity ◽  
Coulomb Type

An investigation of thickness dependence of the X-ray integrated intensity of monochromatic linearly polarised X-ray radiation in a symmetrical Laue-case diffraction reveals that the method of determination of structure factors f from thickness oscillations can be extended to real crystals with a static distribution of Coulomb-type defects or dislocations. The f E value (where E is the static Debye-Waller factor) is determined from the oscillation period, while E is determined from the tilt-angle tangent of the oscillation axis of the reduced integrated intensity.

scholarly journals Atomic disorder of Li0.5Ni0.5O thin films caused by Li doping: estimation from X-ray Debye–Waller factors

2015 ◽  
Vol 48 (6) ◽  
pp. 1896-1900 ◽  
Author(s):  
Anli Yang ◽  
Osami Sakata ◽  
Ryosuke Yamauchi ◽  
L. S. R. Kumara ◽  
Chulho Song ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Debye Model ◽  
Waller Factor ◽  
Structural Parameter ◽  
X Ray Diffraction ◽  
Atomic Disorder ◽  
X Ray ◽  
Li Doping ◽  
Debye Waller Factor

Cubic type room-temperature (RT) epitaxial Li0.5Ni0.5O and NiO thin films with [111] orientation grown on ultra-smooth sapphire (0001) substrates were examined using synchrotron-based thin-film X-ray diffraction. The 1\overline{1}1 and 2\overline{2}2 rocking curves including six respective equivalent reflections of the Li0.5Ni0.5O and NiO thin films were recorded. The RTB1factor, which appears in the Debye–Waller factor, of a cubic Li0.5Ni0.5O thin film was estimated to be 1.8 (4) Å2from its 1\overline{1}1 and 2\overline{2}2 reflections, even though the Debye model was originally derived on the basis of one cubic element. The corresponding Debye temperature is 281 (39) K. Furthermore, theB2factor in the pseudo-Debye–Waller factor is proposed. This parameter, which is evaluated using one reflection, was also determined for the Li0.5Ni0.5O thin film by treating Li0.5Ni0.5O and NiO as ideal NaCl crystal structures. A structural parameter for the atomic disorder is introduced and evaluated. This parameter includes the combined effects of thermal vibration, interstitial atoms and defects caused by Li doping using the two Debye–Waller factors.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

Crystal structure determination of solar cell materials: Cu2ZnSnS4 thin films using X-ray anomalous dispersion

2012 ◽  
Vol 524 ◽  
pp. 22-25 ◽  
Author(s):  
Hiroshi Nozaki ◽  
Tatsuo Fukano ◽  
Shingo Ohta ◽  
Yoshiki Seno ◽  
Hironori Katagiri ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Solar Cell ◽  
Structure Determination ◽  
Anomalous Dispersion ◽  
Crystal Structure Determination ◽  
X Ray

Properties of Epitaxial SrTiO3 Thin Films Grown on Silicon by Molecular Beam Epitaxy

1999 ◽  
Vol 567 ◽  
Author(s):  
Z. Yu ◽  
R. Droopad ◽  
J. Ramdani ◽  
J.A. Curless ◽  
C.D. Overgaard ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
State Density ◽  
Unit Cell ◽  
Ex Situ ◽  
Silicon Oxide Layer ◽  
Single Crystalline ◽  
X Ray

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.

scholarly journals Atomic structure and phason modes of the Sc–Zn icosahedral quasicrystal

IUCrJ ◽  
2016 ◽  
Vol 3 (4) ◽  
pp. 247-258 ◽  
Author(s):  
Tsunetomo Yamada ◽  
Hiroyuki Takakura ◽  
Holger Euchner ◽  
Cesar Pay Gómez ◽  
Alexei Bosak ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Diffuse Scattering ◽  
Waller Factor ◽  
Close Packing ◽  
Icosahedral Quasicrystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Large Atom ◽  
Debye Waller Factor ◽  
The Difference

The detailed atomic structure of the binary icosahedral (i) ScZn7.33quasicrystal has been investigated by means of high-resolution synchrotron single-crystal X-ray diffraction and absolute scale measurements of diffuse scattering. The average atomic structure has been solved using the measured Bragg intensity data based on a six-dimensional model that is isostructural to the i-YbCd5.7one. The structure is described with a quasiperiodic packing of large Tsai-type rhombic triacontahedron clusters and double Friauf polyhedra (DFP), both resulting from a close-packing of a large (Sc) and a small (Zn) atom. The difference in chemical composition between i-ScZn7.33and i-YbCd5.7was found to lie in the icosahedron shell and the DFP where in i-ScZn7.33chemical disorder occurs on the large atom sites, which induces a significant distortion to the structure units. The intensity in reciprocal space displays a substantial amount of diffuse scattering with anisotropic distribution, located around the strong Bragg peaks, that can be fully interpreted as resulting from phason fluctuations, with a ratio of the phason elastic constantsK2/K1= −0.53,i.e.close to a threefold instability limit. This induces a relatively large perpendicular (or phason) Debye–Waller factor, which explains the vanishing of `high-Qperp' reflections.

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