Effect of Ga Substitution on the Γ3 Doublet Ground State in PrIr2Zn20. (January 2016) - Onimaru, Takahiro
Abstract: Electrical resistivity ρ, specific heat C, and magnetic susceptibility χ measurements are reported on PrIr2 Zn20– x Ga x for x =0.5 and 1.0. On cooling, ρ(T) 's monotonically decrease to the residual values which are two orders of magnitudes larger than that of PrIr2 Zn20 . A broad hump in C m (T) 's at around 10 K can be reproduced by the two-level model with the Γ3 doublet ground state and the Γ4 triplet excited state. The magnetic entropy release shifts to higher temperatures with increasing x . The increase in χ (T) at T < 5 K contrasts with the saturation of χ (T) for x =0. These observations indicate the splitting of the ground state doublet due to the lowering of the local symmetry at the Pr site by the Ga substitution.