Local tetragonal distortions of the (CrF6)3− and (FeF6)3− octahedral clusters in Cr3+- and Fe3+-doped tetragonal Rb2KGaF6 crystals. Issue 3 (3rd April 2017)

• Record Type: Journal Article
• Authors: Zhou, Ya-Wen; Yang, Li-Rong; Tang, Jie; Mei, Yang
• Is Part Of: Radiation effects and defects in solids. Volume 172:Issue 3/4(2017)
• Page Start: 337
• Page End: 341
• Publication Date: 2017-04-03
• Subjects: Defects -- local distortion -- electron paramagnetic resonance -- Cr3+ -- Fe3+ -- Rb2KGaF6; Radiation chemistry -- Periodicals; Crystals -- Defects -- Periodicals; Crystal lattices -- Periodicals; 530.416
• DOI: 10.1080/10420150.2017.1320399
• Languages: English
• ISSNs: 1042-0150

Abstract

ABSTRACT: The local tetragonal distortions ( α − α 0 ) (where α is the angle defined as tg α = R ⊥ / R //, R ⊥ and R // are the metal–ligand distances parallel with and normal to the C4 axis, α 0 = 45° is the same angle in cubic symmetry) of (CrF6 ) 3− and (FeF6 ) 3− octahedral clusters in the tetragonal Rb2 KGaF6 crystals are estimated by analyzing their electron paramagnetic resonance (EPR) zero-field splittings D . The results indicate that the two impurity octahedra and hence the host (GaF6 ) 3− octahedra are tetragonally elongated. The distortion ( α − α 0 ) in magnitude differs from impurity to impurity because of the different sizes and natures of these impurities. These results are analogous to those in ABX3 and doped ABX3 perovskite crystals where the cubic-to-tetragonal phase transition is due to the rotation of BX6 octahedra associated with the release or elongation of B–X bond along the C4 rotational axis.