Special quasirandom structures to study the (K0.5Na0.5)NbO3 random alloy

Date
2014-07-01
Authors
Voas, Brian
Usher, Tedi-Marie
Tan, Xiaoli
Liu, Xiaoming
Li, Shen
Jones, Jacob
Tan, Xiaoli
Cooper, Valentino
Beckman, Scott
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Tan, Xiaoli
Person
Research Projects
Organizational Units
Journal Issue
Series
Department
Materials Science and Engineering
Abstract

The local structure of K0.5Na0.5NbO3 is investigated using first-principles methods with an optimized special quasirandom structure (SQS). Through a comparison of the computed pair distribution functions with those from neutron powder diffraction data, the SQS approach demonstrates its ability to accurately capture the local structure patterns derived from the random distribution of K and Na on the perovskite A-site. Using these structures, local variations in Na-O interactions are suggested to be the driving force behind the R3c to Pm phase transition. A comparison between the SQS and a rocksalt structure shows the inability of the latter to account for the local variability present in a random solid solution. As such, the predictive nature of the SQS demonstrated here suggests that this approach may provide insight in understanding the properties of a wide range of bulk oxide alloys or solid solutions.

Comments

This article is from Physical Review B 90 (2014): 1, doi:10.1103/PhysRevB.90.024105. Posted with permission.

Description
Keywords
Citation
DOI
Collections