Zero-field splittings and local tilting angles tau(Mn2+) for Mn2+ in ZnGeP2 and CdGeP2 crystals

摘要

The electron paramagnetic resonance (EPR) zero-field splittings (ZFSs) D of Mn2+ in ZnGeP2 and CdGeP2 crystals are calculated from both the microscopic spin-orbit coupling mechanism and the empirical superposition model. From the calculations, the ZFS D of ZnGeP2:Mn2+ is reasonably explained by using the local tilting angle tau(Mn2+) (rather than the corresponding angle tau(Zn2+) in the host crystal) and the local tilting angle tau(Mn2+) (which has not been reported) in CdGeP2:Mn2+ is estimated. The intrinsic ZFS parameter (b) over bar (2) (R-0) approximate to -0.052(6) cm(-1) (with R-0 approximate to 2.43 angstrom A) is suggested for Mn2+-P3- combination by using the local tilting angles tau(Mn2+). The value is quite unlike that (approximate to 0.4(2) cm(-1)) obtained in the previous paper by combining the crystallographic data of host crystals with the ZFSs for Mn2+ ions in crystals. The reasonableness of these results is discussed. (c) 2008 Elsevier B.V. All rights reserved.