Electron Spin Resonance Of Er3+ In Ybipt

Electron spin resonance (ESR) experiments at 4.15 K of Er(3+) in YBiPt show that Er(3+) is in a site of cubic local symmetry, with a Gamma(8)((3)) ground state and an overall crystal field splitting of similar to 85(10) K. We inferred from the spectra the existence of lattice distortions at the rare-earth (RE) site. These results may help in understanding the heavy-fermion system YbBiPt, which has the same structure as YBiPt.