Eur. Phys. J. D 58, 281-285 (2010)
https://doi.org/10.1140/epjd/e2010-00115-7

Investigations of the local lattice distortions and the EPR parameters for the orthorhombic Pt³⁺ center in YAG

¹ Department of Applied Physics, University of Electronic Science and Technology of China, 610054, Chengdu, P.R. China
² International Centre for Materials Physics, Chinese Academy of Sciences, 110016, Shenyang, P.R. China

Corresponding author: ^a shaoyi_wu@163.com

Received: 26 November 2009
Revised: 22 March 2010
Published online: 5 May 2010

Abstract

The local lattice distortions and the EPR parameters (anisotropic g factors and the hyperfine structure constants) for the orthorhombic Pt³⁺ center in YAG are theoretically investigated from the perturbation formulas of these parameters for a 5d⁷ ion in an orthorhombically elongated octahedron. The [ PtO₆] ^9- cluster on Al³⁺ site is found to experience the axial elongation of about 0.01 Å along Z axis, and the planar impurity-ligand bond lengths suffer the relative variation of about 0.11 Å  along X and Y axes due to the Jahn-Teller effect. As a result, the above local lattice distortions produce significant orthorhombic deformation, whereas the original slight trigonal distortion of the host [ AlO₆ octahedron is entirely depressed by the Jahn-Teller effect. The calculated EPR parameters based on the above lattice distortions show good agreement with the experimental data, and the local structure of the impurity center is also discussed.