The g-value of Er3+ doped unfilled skutterudite CoSb3 (T-h) reveals the existence of an additional sixth order term in the crystal field Hamiltonian

摘要

Electron spin resonance (ESR) experiments have been carried out in single crystals of the unfilled skutterudite CoSb3 doped with Er ions. The X- (9.5 GHz) and Q- (34.4 GHz) band spectra obtained at low temperature (4-20 K) shown a temperature independent g-value of 6.21(5). This g-value can only be explained with the addition of a second sixth order B-6(1)(O-6(2) - O-6(6)) term to the usual cubic crystal field Hamiltonian. The ESR of Er3+ show the typical temperature dependence of the line-shape and line-width expected for insulating host.