EPR investigation of local structure for the [Mn(H₂O)₆]²⁺ cluster in M(ClO₄)₂ · 6H₂O:Mn²⁺ (M = Cd, Hg) systems at different temperatures

¹ School of Science, Southwest Petroleum University, Chengdu 610065, P.R. China
² Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, P.R. China

^a e-mail: scu_ljf@163.com

Received: 31 August 2014
Accepted: 5 January 2015
Published online: 14 August 2015

Abstract

Local lattice structure distortion studies of the octahedral Mn²⁺ center in M(ClO₄)₂ · 6H₂O:Mn²⁺ (M = Cd, Hg) systems have been performed systematically based on the diagonalization of the complete energy matrices of electron-electron repulsion, spin-orbit coupling and trigonal ligand-field interaction for a d⁵ configuration ion in a trigonal ligand field. From the EPR calculation, the local structure distortion parameters R and θ are determined, respectively. Results show that the local lattice structure around a trigonal Mn²⁺ center has a compressed distortion along the crystalline C₃ axis. The compression distortion may be ascribed to the fact that the radius of the Mn²⁺ ion is smaller than that of the Hg²⁺ ion and the Cd²⁺ ion. The local lattice structure parameters for Mn²⁺ in M(ClO₄)₂ · 6H₂O:Mn²⁺ (M = Cd, Hg) systems are determined at liquid-nitrogen temperature and room temperature.