Determination of Al occupancy and local structure for β-(AlxGa1−x)2O3 alloys across nearly full composition range from Rietveld analysis

Author:

Bhattacharjee Jayanta12ORCID,Sagdeo Archna12ORCID,Singh S. D.12ORCID

Affiliation:

1. Synchrotrons Utilization Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India

2. Homi Bhabha National Institute, Anushkati Nagar, Mumbai 400094, India

Abstract

Al occupancy and local structure (bond lengths and bond angles) for monoclinic β-(AlxGa1−x)2O3 alloys, with Al compositions (x) up to 90%, have been determined from Rietveld refinement of x-ray diffraction data. An Al atom preferentially occupies an octahedron (Oh) atomic site in comparison with a tetrahedron (Td) atomic site. However, a sizable number of Td atomic sites, i.e., 20% for Al composition of 5%, remain occupied by Al atoms, which is found to increase sharply with Al composition. The Oh atomic sites are not fully occupied by Al atoms even for the Al composition of 90%. The lattice parameters (bandgap) of the β-(AlxGa1−x)2O3 alloy decrease (increase) linearly with Al composition, but a change in slope of the variation of both lattice parameters and bandgap is observed at around Al composition of 50%. The lattice is found to be distorted for Al compositions more than 50% as indicated by a large change in the bond angles. The lattice distortion is determined to be the origin for the observed change in slope of the variation of both lattice parameters and bandgap for a monoclinic β-(AlxGa1−x)2O3 alloy system. Our results provide an insight into the local structure of β-(AlxGa1−x)2O3 alloys, which are required to have better understanding of their physical properties.

Publisher

AIP Publishing

Subject

Physics and Astronomy (miscellaneous)

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3