Computer program superposition model-Monte Carlo (SPM-MC) and its applications in EMR studies of transition ions at low symmetry sites Fe~(3+) doped YAP crystals

摘要

An extension of the computer program superposition model-Monte Carlo (SPM-MC), designed for modelling of the spectroscopic and structural properties of transition ions at low symmetry sites in crystals, is presented. Special focus is put on two aspects. The first aspect concerns the effects of variation of the superposition model (SPM) parameters, i.e. the intrinsic parameters (b_2, b_4) and power low exponents (t_2, t_4), on the quality of fittings of experimental data and theoretical predictions. This enables to increase the reliability of the modelling results. The second aspect concerns the implications of low site symmetry on modelling of the pertinent properties. Applications of the program SPM-MC to Fe~(3+) ions at the triclinic (C_i) symmetry sites in YAlO_3 (YAP) crystals are considered.