Crystallinity Studies of GaN/Si Films Grown by MOCVD at Various Substrate Temperatures Using XRD

2006 ◽  
Vol 517 ◽  
pp. 69-72
Author(s):  
Sha Shiong Ng ◽  
Hassan Zainuriah ◽  
Abu Hassan Haslan ◽  
M.E. Kordesch
Keyword(s):  
Crystalline Structure ◽  
Growth Temperature ◽  
Structure Type ◽  
X Ray Diffraction ◽  
General Picture ◽  
X Ray ◽  
Si Films ◽  
Substrate Temperatures ◽  
Deposited Films

In this paper, we report on the characterization of a set of MOCVD grown GaN samples with a variety of structural or crystalline quality. X-ray diffraction (XRD) was used to observe the change of the crystalline structure with deposition temperature. All results show that the structure type of the GaN deposited films is sensitive to the growth temperature. Our results also revealed that a good crystalline structure of GaN films could be grown at temperatures higher than 600°C. Finally, a general picture on the correlations between the growth temperature and the GaN deposited films crystalline is reported.

Synthesis and Structural Characterization of Ca14NbxIn1-xAs11 (x ≈ 0.85)

2016 ◽  
Vol 257 ◽  
pp. 147-151 ◽  
Author(s):  
Yi Wang ◽  
Svilen Bobev
Keyword(s):  
Physical Properties ◽  
Side Reaction ◽  
Structure Type ◽  
Major Product ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ongoing Work ◽  
Set Up

Single-crystals of the new compound Ca14NbxIn1–xAs11 have been obtained from a solid-state reaction in a sealed Nb ampoule. The initial experiment had been set up with the aim to investigate the effect of electron doping (via In) on the crystal structure and physical properties of Ca14MnAs11. Subsequent single-crystal X-ray diffraction and elemental analysis work suggested that instead of Ca14MnxIn1–xAs11, the major product of the reaction is the phase Ca14NbxIn1–xAs11. This supposition was corroborated when the title compound was synthesized from a reaction of Ca, In and As in a sealed Nb ampoule, proving that, 1) Mn metal is not included in the structure, and 2) that the inadvertent side reaction of As with the walls of the Nb container is the source of the niobium. The overall structure is isotypic with the tetragonal Ca14AlSb11 structure type (space group I41/acd), although some marked differences between the two must be noted. Current ongoing work is focused on the synthesis of phase pure polycrystalline samples and determination of the physical properties of this unusual transition metal Zintl phase.

The Effect of Sample Substrate on the Structural Properties of Co-Deposited Films of A-Ge:H

1990 ◽  
Vol 192 ◽  
Author(s):  
S.J. Jones ◽  
W.A. Turner ◽  
D. Pang ◽  
W. Paul
Keyword(s):  
Yield Strength ◽  
Crystallization Process ◽  
Exothermic Peak ◽  
High Yield ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Strength Differential ◽  
Substrate Temperatures ◽  
Deposited Films

ABSTRACTResults from structural measurements on r.f. glow discharge produced a-Ge:H films have been found to be substrate dependent. The variations in the results were found to depend on both the substrate temperature, Ts, and the substrate yield strength. Differential scanning calorimetry results were particularly affected by these parameters. For films prepared at Ts = 150°C, the DSC spectra contain two exothermic peaks when the films are deposited on low yield strength substrates while only one exothermic peak is present for films deposited on high yield strength substrates. One exothermic DSC peak is seen in spectra for all films prepared at Ts = 300°C no matter what substrates were used. This DSC spectral dependence is attributed to differences in the microstructure of films deposited at the two substrate temperatures, as seen in TEM micrographs. X-ray diffraction measurements performed on films annealed to various temperatures show that all of the exothermic DSC peaks described above are associated with the crystallization process. Thus, for the films prepared at low Ts, crystallization is either a one or two step process depending on the yield strength of the substrate.

scholarly journals Synthesis and superstructural characterization of Fe1.89Mo4.11O7

1994 ◽  
Vol 9 (4) ◽  
pp. 891-897 ◽  
Author(s):  
George L. Schimek ◽  
Robert E. McCarley ◽  
L. Scott Chumbley
Keyword(s):  
Structure Type ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Cation Site ◽  
X Ray ◽  
Transmission Electron ◽  
The Family ◽  
Regular Arrangement ◽  
Cation Sites

Superstructuring in the new compound Fe1.89Mo4.11O7 has been elucidated by transmission electron microscopy. This compound is a member of the family M2MO4O7 and has both iron and molybdenum atoms occupying octahedrally coordinated sites in the structure, represented by Fet(Fe0.89M0.11)0Mo4O7. The superstructuring, detected only by electron diffraction, involved tripling of all three lattice parameters of the subcell. The subcell was structured by single crystal x-ray diffraction [Imma, no. 74, a = 5.9793(5) Å, b = 5.7704(4) Å, and c = 17.036(1) Å]. This structure type contains a close-packed arrangement of Mo4O7 units, which are infinite chains of trans edge-shared molybdenum octahedra running parallel to b*. Two different coordination environments are observed for the cations. Parallel to the a* direction, infinite edge-sharing MO6 (M = 89% Fe or 11% Mo) octahedra are observed. The second cation site, with nearly tetrahedral coordination by oxygen, is filled solely by iron. The superstructure can be rationalized by a regular arrangement of iron and molybdenum atoms in the octahedrally coordinated cation sites.

EBSD Analysis of SmCoFeCuZr Alloys

2016 ◽  
Vol 869 ◽  
pp. 608-613
Author(s):  
Sergio Antonio Romero ◽  
Christien G. Hauegen ◽  
Fernando J.G. Landgraf ◽  
Marcos Flavio de Campos
Keyword(s):  
Texture Analysis ◽  
Crystalline Structure ◽  
Ebsd Analysis ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Complementary Technique ◽  
X Ray ◽  
Kikuchi Lines

In the present study, EBSD was used for the characterization of alloys used for production of SmFeCoCuZr magnets. EBSD is adequate for texture analysis, but may give misleading results for phase identification. EBSD is not suitable for identifying phases with very similar crystalline structure, especially when the phases are crystallographically coherent, due to the superposition of Kikuchi lines. As consequence, for phase identification EBSD should be considered a complementary technique to other methods, as for example x-ray diffraction (XRD).

Microstructure and Properties of CoSi2 Thin Films on (100) Silicon by Laser Physical Vapor Deposition

1992 ◽  
Vol 285 ◽  
Author(s):  
P. Tiwari ◽  
R. Chowdhury ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure And Properties ◽  
Transmission Electron ◽  
Substrate Temperatures ◽  
Deposited Films

ABSTRACTLaser physical vapor deposition (LPVD) has been used to deposit thin CoSi2 films on (001)silicon at different substrate temperatures ranging from room temperature to 600°C. Particulate-free silicide thin films were characterized by X-ray diffraction, Rutherford backscattering, and high resolution transmission electron microscopy. We have found that films deposited at 200°C and below are amorphous; 400°C deposited films are polycrystalline whereas films deposited at 600°C are of epitaxial nature. The Effect of subsequent annealing on resistivity of room-temperature deposited thin films has been investigated. The resistivity value decreases to less than 15 μΩcm after annealing making these films suitable for microelectronics applications. The correlation between microstructure and properties of these films are discussed.

Synthesis and Characterization of MoS2 Thin Films Grown by Pulsed Laser Evaporation

1988 ◽  
Vol 140 ◽  
Author(s):  
M. S. Donley ◽  
P. T. Murray ◽  
N. T. McDevitt
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Plasma Temperature ◽  
Laser Evaporation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plot Analysis ◽  
Glancing Angle ◽  
Substrate Temperatures

AbstractThe growth and characterization of MoS thin films grown by pulsed laser evaporation is investigated. TOF anafysis of the ions evaporated from an MoS2 target indicates that PLE results primarily in the evaporation of atomic Mo and S species; MoxSy clusters were also detected, but were present at a significantly Iower intensity. TOF velocity analysis indicates an effective plasma temperature of 1500K. Stoichiometric MoS2 films were grown at substrate temperatures between room temperature and 500ºC under the above laser conditions. XPS data is used to develop a Wagner chemical state plot. Analysis of the films by Raman spectroscopy and glancing angle x-ray diffraction indicates the films to be crystalline, hexagonal MoS2, with a tendency for basal plane orientation parallel to the substrate.

scholarly journals PREPARATION AND CHARACTERIZATION OF CDO-NIO NANOCOMPOSITES USING LASER PULSE DEPOSITION APPROACH

2021 ◽  
Vol 03 (03) ◽  
pp. 01-09
Author(s):  
Khamees D. MAHMOOD ◽  
Kadhim A. AADIM ◽  
Mohammed G. HAMMED
Keyword(s):  
Laser Pulse ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pulse Deposition ◽  
Deposited Films

In this manuscript, CdO-NiO nanocomposites (in the form of thin film) with particular concentrations are paper using laser pulse deposition technique under the effect of different laser energies (300, 400, 500, and 600 mJ). Furthermore, the structural, morphological, and optical analyses are thoroughly investigated. In particular, well-oriented deposited films are observed by using X-ray diffraction technique, while the morphological properties are investigated using two different techniques namely field emission scanning electron microscopy and atomic force microscopy which have revealed small nanoparticles with approximate diameter of 50 nm and average surface roughness ranging between 6.5 and 20.3 nm for laser energies of 400 and 600 mJ, respectively. Continuously, the optical technique applied which used UV-Vis analysis has showed cut-off phenomenon at around 339 nm. In the meanwhile, the energy band gap for the deposited films was found to be within the range of 2.2 and 2.4 eV, as a result of different laser energies.

Vacuum Pressure MOVCD Growth and Characterization of AlN Films On MgO(100), Sapphire, and Si

1997 ◽  
Vol 482 ◽  
Author(s):  
A. D. Serra ◽  
N. P. Magtoto ◽  
D. C. Ingram ◽  
H. H. Richardson
Keyword(s):  
Electron Microscopy ◽  
Reflectance Spectroscopy ◽  
Vacuum Pressure ◽  
Ex Situ ◽  
Infrared Reflectance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Substrate Temperatures ◽  
Scanning Electron

abstractFilms of AlN were grown on MgO(100), Al2O3, and Si under vacuum pressure (10-3 to 10-4 Torr) at different substrate temperatures. They were examined ex situ with infrared reflectance spectroscopy, scanning electron microscopy, x-ray diffraction and rutherford backscattering spectroscopy. Highly oriented smooth films were grown at film thicknesses below 1 μm. Thicker films showed significantly more roughness but remained oriented with respect to the substrate. AIN growth was faster on Si than MgO(100) or Al2O3 and Si was the only substrate that growth was observed at 500°C.

Spectroscopic and Structural Studies of Some Precursors for the Deposition of PZT and Related Materials by MOCVD

1997 ◽  
Vol 495 ◽  
Author(s):  
Kirsty A. Fleeting ◽  
Tony C. Jones ◽  
Tim Leedham ◽  
M. Azad Malik ◽  
Paul O'brien ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Lead Zirconium Titanate ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
Chemical Methods ◽  
X Ray ◽  
Mocvd Precursors ◽  
And Control ◽  
Substrate Temperatures

ABSTRACTMOCVD is a useful method for the deposition of thin films of lead zirconium titanate, PZT, because of its good step coverage and control of composition. Results are herein presented on a number of novel compounds which are potential MOCVD precursors. The compounds studied include Pb(tmhd)2, Zr(OBu')4 and Ti(OPr')4. Another commonly utilized precursor Zr(tmhd)4, is not ideal, in that it is a high melting point solid, and hence requires high substrate temperatures. We have sought to modify Zr precursors through chemical methods and have synthesized a number of novel, more volatile, and less intrinsically thermally stable MOCVD precursors. Full chemical characterization of the Zr precursors (NMR, IR, MS, CHN, TGA/DSC, Single Crystal X-ray diffraction) has been undertaken. We also present structural results on some related lead precursors.

Structural Characterization of Laser-Annealed Sputtered Poly-Si Films for High Mobility Tfts

1990 ◽  
Vol 202 ◽  
Author(s):  
Akio Okamoto ◽  
Seiiti Shirai ◽  
Shiro Suyama ◽  
Tadashi Serikawa
Keyword(s):  
Structural Characterization ◽  
Crystal Orientation ◽  
High Mobility ◽  
Structural Difference ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputtered Films ◽  
Fine Grain ◽  
Si Films

ABSTRACTA high mobility of 390 cm2/Vs was successfully obtained for sputtered films, compared with 100 cm2/Vs for CVD films. Then, structural characterization of laser-annealed sputtered silicon films were performed, and compared with that of CVD films. TEM observations show a structural difference between the two film types. In sputtered films, many fine grain-like regions which have slightly different crystal orientation from surrounding regions are observed. On the other hand, in the CVD films, defects are widely spread over the film. X-ray diffraction, Raman scattering, and SIMS yield almost the same results in both films. The above-mentioned structural difference is thought to be essential to obtain high mobility.

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