Analysis of the local structure around Cr3+ centers in perovskite KMgF3 using both ab initio (DFT) and semi-empirical (SPM) calculations

Emul Y., Erbahar D., Acikgoz M.

CHEMICAL PHYSICS, cilt.444, ss.52-60, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 444
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1016/j.chemphys.2014.10.003
  • Dergi Adı: CHEMICAL PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.52-60
  • Sivas Cumhuriyet Üniversitesi Adresli: Evet

Özet

The local structure around Cr3+ centers in perovskite KMgF3 crystal have been investigated through the applications of both an ab-initio, density functional theory (DFT), and a semi empirical, superposition model (SPM), analyses. A supercell approach is used for DFT calculations. All the tetragonal (Cr3+-V-Mg and Cr3+-Li+), trigonal (Cr3+-V-K), and CrF5O cluster centers have been considered with various structural models based on the previously suggested experimental inferences. The significant structural changes around the Cr3+ centers induced by Mg2+ or K+ vacancies and the Li substitution at those vacancy sites have been determined and discussed by means of charge distribution. This study provides insight on both the roles of Mg2+ and K+ vacancies and Li+ ion in the local structural properties around Cr3+ centers in KMgF3. (c) 2014 Elsevier B.V. All rights reserved.