A computer simulation approach for the calculation of diffuse intensity distributions from crystals undergoing the 2H to 6H transformation by layer displacement mechanism

Kabra, Vedant; Pandey, Dhananjai

doi:10.1107/s0108767394011517

Cited by 12 publications

(5 citation statements)

References 13 publications

(23 reference statements)

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“…Use of Monte Carlo techniques leads to the same results as those obtained by analytical treatment for random distribution of stacking faults (Berliner & Werner, 1986). However, for non-random distribution of faults, the Monte Carlo results have been shown to be different from those obtained analytically using the difference equation approach especially for large fault probabilities (Kabra & Pandey, 1995. The main difference between the analytical and Monte Carlo approaches is that the latter leads to the arrest of the transformation for an intermediate value of non-random fault probability less than the value of unity required for completion of the transformation.…”

Section: Introductionmentioning

confidence: 79%

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Scaling behaviour of pair correlation functions for randomly faulted hexagonal close-packed structures

Tiwary

Pandey

2007

Acta Cryst Sect A

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Monte Carlo simulations and analytical results are used to demonstrate that the hexagonal close-packed (h.c.p.) pair correlation functions for different values of randomly distributed growth and deformation faults can be collapsed into master curves when plotted against a spatial variable, scaled with respect to a characteristic length (L). The functional dependences of L on different types of faults are found to be non-universal. A simple method for the determination of L from the measured intensity distributions is also outlined.

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Section: Introductionmentioning

confidence: 79%

“…3(a). crystals which always retain longrange correlations (Sato, 1969;Pandey et al, 1980a;Kabra & Pandey, 1995). For > 0.5, the correlation length again starts increasing and, at = 1, the ABABAB .…”

Section: Random Deformation Faultsmentioning

confidence: 99%

Scaling behaviour of pair correlation functions for randomly faulted hexagonal close-packed structures

Tiwary

Pandey

2007

Acta Cryst Sect A

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“…There have been several studies about the effect of SFs in the close-packed structure of polycrystalline metals ranging from theoretical calculations (Berliner & Werner, 1986) to computer simulations (Kabra & Pandey, 1995).…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional reciprocal space mapping of diffuse scattering for the study of stacking faults in semipolar (\bf 11{\overline 2}2) GaN layers grown from the sidewall of anr-patterned sapphire substrate

et al. 2013

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Three-dimensional reciprocal space mapping of semipolar (11{\overline 2}2) GaN grown on stripe-patternedr-plane (1{\overline 1}02) sapphire substrates is found to be a powerful and crucial method for the analysis of diffuse scattering originating from stacking faults that are diffracting in a noncoplanar geometry. Additionally, by measuring three-dimensional reciprocal space maps (3D-RSMs) of several reflections, the transmission electron microscopy visibility criteria could be confirmed. Furthermore, similar to cathodoluminescence, the 3D-RSM method could be used in future as a reliable tool to distinguish clearly between the diffuse scattering signals coming from prismatic and from basal plane stacking faults and from partial dislocations in semipolar (11{\overline 2}2) GaN. The fitting of the diffuse scattering intensity profile along the stacking fault streaks with a simulation based on the Monte Carlo approach has delivered an accurate determination of the basal plane stacking fault density. A reduction of the stacking fault density due to the intercalation of an SiN interlayer in the GaN layer deposited on the sidewall of the pre-patterned sapphire substrate has led to an improvement of the optoelectronic properties, influenced by the crystal quality, as has been demonstrated by a locally resolved cathodoluminescence investigation.

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“…The simulation is similar to those used to study the hcp to fcc transition in Co and its alloys. 28,29 The model transformation was a effected in small domains picked at random within the 1350 planes of the film. A close-packed plane was coded by p ϭ1(A),2(B), or 3(C) and could be slid via…”

Section: A B C a B C A B C ⇓ A B A B C A B C A ⇓ A B A B C B C A B ⇓ mentioning

confidence: 99%

Epitaxial Ce and the magnetism of single-crystal Ce/Nd superlattices

Clegg¹,

Goff

McIntyre

et al. 2003

Phys. Rev. B

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The chemical structure of epitaxial ␥ cerium and the chemical and magnetic structures of cerium/ neodymium superlattices have been studied using x-ray and neutron diffraction techniques. The samples were grown using molecular-beam epitaxy, optimized to yield the desired Ce allotropes. The x-ray measurements show that, in the superlattices, both constituents adopt the dhcp structure and that the stacking sequence remains intact down to Tϳ2 K; these are the first measurements of magnetic ordering in single-crystal dhcp Ce. The magnetic structure of the superlattices with thicker Nd layers exhibit incommensurate order and ferromagnetism on separate sublattices in a similar manner to Nd under applied pressure. The sample with thickest Ce layers has a magnetic structure similar to bulk ␤ Ce, which has commensurate transverse modulation with a propagation wave vector ͓1/2 0 0͔ and moments along the hexagonal a direction. These two types of magnetic order appear to be mutually exclusive. ␥ Ce is the high-temperature fcc phase of Ce, our singlephase epitaxial sample is observed to go through a new, but partial, structural transition not previously seen in the bulk material.

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A computer simulation approach for the calculation of diffuse intensity distributions from crystals undergoing the 2H to 6H transformation by layer displacement mechanism

Cited by 12 publications

References 13 publications

Scaling behaviour of pair correlation functions for randomly faulted hexagonal close-packed structures

Scaling behaviour of pair correlation functions for randomly faulted hexagonal close-packed structures

Three-dimensional reciprocal space mapping of diffuse scattering for the study of stacking faults in semipolar (\bf 11{\overline 2}2) GaN layers grown from the sidewall of anr-patterned sapphire substrate

Epitaxial Ce and the magnetism of single-crystal Ce/Nd superlattices

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