Influence of ligand spin–orbit coupling to the sign of the zero-field splitting and pressure-induced spectral shift for ZnS:Mn2+ (bulk/nanocrystal)

Abstract

Abstract Serious difficulties exist in explaining the zero-field splitting (ZFS) of 3d 5 ions in crystal, with the current crystal-field theory. The calculated cubic ZFS a -value of 3d 5 ion is positive identically. However, K.A. Muller and W. Low found experimentally that a is negative for some ZnS:Mn 2+ crystals. In this work, an unified explanation is developed for the ZFS, optical spectra and pressure-induced spectral shift for the ZnS:Mn 2+ (bulk/nanocrystal) by considering the influence of the spin–orbit coupling to the ZFS and spectral bands. The excellent agreement between calculation and experiments shows that the above-mentioned difficulties can be removed based on the calculation model proposed by authors. Calculation result shows that there are two kinds of stable electron states with ( λ π , λ σ , λ s ) = (0.2713448, −0.1619936, −0.08) and (0.2713448, 0.346885, −0.220), respectively, where ( λ π , λ σ , λ s ) denote the mixing coefficients of Mn 2+ − 4S 2− anti-bonding in ZnS:Mn 2+ .