Studies on the axial shift and the spin Hamiltonian parameters for Cr⁺ in BeO

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

^a e-mail: btsong1@gmail.com

Received: 2 August 2012
Accepted: 11 January 2013
Published online: 20 March 2013

Abstract

The axial shift and the spin Hamiltonian parameters (zero-field splitting D, g factors and hyperfine structure constants) for Cr⁺ in BeO are theoretically studied in this work. The calculations are carried out by using the perturbation formulas of these parameters for a 3d⁵ ion under trigonally distorted tetrahedra based on the cluster approach containing both the crystal-field and charge transfer contributions. It is found that the impurity Cr⁺ may not occupy exactly the host Be²⁺ site but experience a small outward shift 0.01 Å away from the ligand triangle along the C₃ axis. The above impurity axial shift leads to much smaller trigonal distortion than the host Be²⁺ site in BeO. The theoretical spin Hamiltonian parameters based on the above impurity axial shift are in good agreement with the observed values.