Open AccessGallium K ‐edge EXAFS measurements on cubic and hexagonal GaN
Author(s) -
Katsikini M.,
Rossner H.,
FieberErdmann M.,
HolubKrappe E.,
Moustakas T. D.,
Paloura E. C.
Publication year - 1999
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s090904959900151x
Subject(s) - gallium , extended x ray absorption fine structure , materials science , hexagonal crystal system , microstructure , relaxation (psychology) , lattice (music) , enhanced data rates for gsm evolution , crystallography , atom (system on chip) , shell (structure) , k nearest neighbors algorithm , condensed matter physics , molecular physics , chemistry , absorption spectroscopy , physics , optics , telecommunications , metallurgy , psychology , social psychology , artificial intelligence , acoustics , embedded system , composite material , computer science
The microstructure of undoped cubic and hexagonal GaN films is studied using temperature dependent Ga K-edge EXAFS measurements (10K-290K). The microstructure around the Ga atom is distorted due to a splitting of the second nearest neighbor shell, which consists of Ga atoms. This splitting results in an additional Ga path at a distance longer than expected by 0.8±0.05 A and is attributed to local lattice relaxation around nitrogen vacancies. From the temperature dependence of the DW factors for the 2 nd nearest neighbor shell of Ga, the Einstein temperature is equal to 318±25K.