Structure and stability of threading edge and screw dislocations in bulk GaN

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F15%3A00473050" target="_blank" >RIV/68081723:_____/15:00473050 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.commatsci.2014.12.013" target="_blank" >http://dx.doi.org/10.1016/j.commatsci.2014.12.013</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.commatsci.2014.12.013" target="_blank" >10.1016/j.commatsci.2014.12.013</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Structure and stability of threading edge and screw dislocations in bulk GaN

Popis výsledku v původním jazyce

Computational studies of a-type threading edge dislocations parallel to the [0001] direction in bulk GaN reveal three possible structures of their cores that are characterized as the 4-atom ring, the 8-atom ring and the 5/7-atom ring configurations. Similar calculations made on the c-type threading screw dislocation suggest the existence of a full core, although the precise structure is still a matter of debate. Most studies associate the position of the dislocation with only high-symmetry points in the lattice and do not discuss the core stability in non-equiatomic configurations. Here, we investigate how the core structures of a-type edge and c-type screw threading dislocations depend on the position in the (0001) plane at which the dislocation is inserted perpendicular to this plane. Furthermore, by successively removing the high-energy atoms from the cores of these dislocations, we track the stability of each core in non-equiatomic configurations and identify the core structures of minimum energy. The edge dislocation is shown to prefer the 5/7-atom ring structure, while the core of the screw dislocation transforms into a new Ga-rich configuration with the associated energy drop of nearly 0.4 eV per one Angstrom of the dislocation length. For all types of dislocation cores found in this paper, we employ isotropic linear elasticity to estimate their core radii and core energies.

Název v anglickém jazyce

Structure and stability of threading edge and screw dislocations in bulk GaN

Popis výsledku anglicky

Computational studies of a-type threading edge dislocations parallel to the [0001] direction in bulk GaN reveal three possible structures of their cores that are characterized as the 4-atom ring, the 8-atom ring and the 5/7-atom ring configurations. Similar calculations made on the c-type threading screw dislocation suggest the existence of a full core, although the precise structure is still a matter of debate. Most studies associate the position of the dislocation with only high-symmetry points in the lattice and do not discuss the core stability in non-equiatomic configurations. Here, we investigate how the core structures of a-type edge and c-type screw threading dislocations depend on the position in the (0001) plane at which the dislocation is inserted perpendicular to this plane. Furthermore, by successively removing the high-energy atoms from the cores of these dislocations, we track the stability of each core in non-equiatomic configurations and identify the core structures of minimum energy. The edge dislocation is shown to prefer the 5/7-atom ring structure, while the core of the screw dislocation transforms into a new Ga-rich configuration with the associated energy drop of nearly 0.4 eV per one Angstrom of the dislocation length. For all types of dislocation cores found in this paper, we employ isotropic linear elasticity to estimate their core radii and core energies.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Computational Materials Science

ISSN

0927-0256

e-ISSN

—

Svazek periodika

99

Číslo periodika v rámci svazku

MAR

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

195-202

Kód UT WoS článku

000349680100026

EID výsledku v databázi Scopus

2-s2.0-84921492083