An X-ray diffraction technique for analyzing basal-plane stacking faults in GaN

2010 ◽  
Vol 207 (11) ◽  
pp. 2446-2455 ◽  
Author(s):  
Qing S. Paduano ◽  
David W. Weyburne ◽  
Alvin J. Drehman
Keyword(s):  
Basal Plane ◽  
Stacking Faults ◽  
X Ray Diffraction ◽  
X Ray

X-ray characterisation of the basal stacking fault densities of (11-22) GaN

CrystEngComm ◽  
2021 ◽  
Author(s):  
Markus Pristovsek ◽  
Martin Fentrup ◽  
Tongtong Zhu ◽  
Gunnar Kusch ◽  
Colin Humphreys
Keyword(s):  
Basal Plane ◽  
Stacking Faults ◽  
Stacking Fault ◽  
X Ray Diffraction ◽  
X Ray

Basal plane stacking faults (BSF) in GaN (11-22) layers were observed by a laboratory X-ray diffraction (XRD) system. For this, the (11-22) GaN was oriented in the [-12-10] zone for...

Investigations on Polytype Stability and Dislocation Formation in 4H-SiC Grown by PVT

2008 ◽  
Vol 600-603 ◽  
pp. 11-14 ◽  
Author(s):  
Erwin Schmitt ◽  
Thomas L. Straubinger ◽  
Michael Rasp ◽  
Michael Vogel ◽  
Andreas Wohlfart
Keyword(s):  
Electron Microscopy ◽  
Optical Microscopy ◽  
Material Properties ◽  
Basal Plane ◽  
Stacking Faults ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Defect Reduction ◽  
X Ray ◽  
Entire Process

We carried out investigations to elucidate the reasons for polytype changes in 4H. The aim was to sustain polytype stability throughout the entire process. The investigations were accompanied by studies on the formation of basal plane dislocations and their role as source for stacking faults. Several methods for the evaluation of material properties were applied to determine quality most precisely, e.g. KOH-defect-etching, optical microscopy, electron microscopy and X-ray-diffraction. We found out that several influences in growth conditions have to be controlled in a proper manner to achieve defect reduction. Based on these investigations we were able to improve our process and the crystal quality significantly. Best values for 3” 4H wafers show that EPD = 5x103 cm-2 , MPD < 0.1 cm-2 and FWHM-values < 15 arcsec can be achieved.

Defect structures of Nb1+αS2 sulfidation scales

1992 ◽  
Vol 50 (1) ◽  
pp. 38-39
Author(s):  
Chuxin Zhou ◽  
L. W. Hobbs
Keyword(s):  
Stacking Faults ◽  
Rhombohedral Structure ◽  
Stacking Sequence ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Normal ◽  
Lower Case ◽  
Sulfur Layer ◽  
Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

Microstructure and Physical Properties of Clay-Polymer Composites

2000 ◽  
Vol 628 ◽  
Author(s):  
T.N. Blanton ◽  
D. Majumdar ◽  
S.M. Melpolder
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Polymer Composites ◽  
Basal Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layered Clay

ABSTRACTClay-polymer nanoparticulate composite materials are evaluated by the X-ray diffraction technique. The basal plane spacing provided information about the degree of intercalation and exfoliation of the 2: 1 layered clay structure. Both intercalation and exfoliation are controlled by the identity of the polymer and the clay:polymer ratio.

Investigation of Residual Strains of the Second Kind in Plastically Deformed Metallic Materials

1994 ◽  
Vol 376 ◽  
Author(s):  
M. Vrána ◽  
P. Klimanek ◽  
T. Kschidock ◽  
P. Lukáš ◽  
P. Mikula
Keyword(s):  
High Resolution ◽  
Neutron Diffraction ◽  
Stacking Faults ◽  
Metallic Materials ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutron Diffractometer ◽  
Residual Strains ◽  
Good Agreement

ABSTRACTInvestigation of strongly distorted crystal structures caused by dislocations, stacking-faults etc. in both plastically deformed f.c.c. and b.c.c. metallic materials was performed by the analysis of the neutron diffraction line broadening. Measurements were realized by means of the high resolution triple-axis neutron diffractometer equipped by bent Si perfect crystals as monochromator and analyzer at the NPI Řež. The substructure parameters obtained in this manner are in good agreement with the results of X-ray diffraction analysis.

X-ray Diffraction by a Layer Silicate containing Stacking Faults

Nature ◽  
1964 ◽  
Vol 201 (4914) ◽  
pp. 63-64 ◽  
Author(s):  
R. STEADMAN
Keyword(s):  
Stacking Faults ◽  
Layer Silicate ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Solidified Fillings of Nanopores

2005 ◽  
Vol 876 ◽  
Author(s):  
Patrick Huber ◽  
Klaus Knorr
Keyword(s):  
Pore Diameter ◽  
Stacking Faults ◽  
Pore Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Medium Length ◽  
Close Packed Structure ◽  
Packed Structure ◽  
Diffraction Patterns ◽  
Selection Of

AbstractWe present a selection of x-ray diffraction patterns of spherical (He, Ar), dumbbell- (N2, CO), and chain-like molecules (n-C9H20, n-C19H40) solidified in nanopores of silica glass (mean pore diameter 7nm). These patterns allow us to demonstrate how key principles governing crystallization have to be adapted in order to accomplish solidification in restricted geometries. 4He, Ar, and the spherical close packed phases of CO and N2 adjust to the pore geometry by introducing a sizeable amount of stacking faults. For the pore solidified, medium-length chainlike n-C19H40 we observe a close packed structure without lamellar ordering, whereas for the short-chain C9H20 the layering principle survives, albeit in a modified fashion compared to the bulk phase.

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