Moment – Bearing Tb substitution in CePt₂Si₂

The effects of substituting moment-bearing Tb in CePt₂Si₂are reported through X-ray diffraction (XRD), electrical resistivity (ρ(T)), magnetic susceptibility, (χ(T)), and magnetization, (σ(μ₀H)) measurements. XRD results for all compositions of (Ce_1−xTb_x)Pt₂Si₂system indicate a tetragonal CaBe₂Ge₂- type structure with space group P4/nmm. ρ(T) results indicate a rapid evolution from a coherent Kondo lattice for the CePt₂Si₂parent compound to incoherent single-ion Kondo behaviour with substitution of Tb for Ce. However, between 90% and 100% of Tb content, the (Ce_1−xTb_x)Pt₂Si₂system reverts back to stable local - moment, normal metal behaviour. χ(T) data at higher temperature follow the Curie - Weiss relation for all alloy compositions and give effective moment values μ_effwhich increase gradually from the expected values of 2.54 μ_Bfor the Ce³⁺- ion to 9.72 μ_Bfor the Tb³⁺- ion. At low temperature χ(T) data exhibit antiferromagnetism at the Ne^′el temperature T_Nin the concentration range 0.7≤x≤1. Below T_Nthe zero-field-cooled and field-cooled susceptibility bifurcate in a 0.1 T field, suggesting an inhomogeneous magnetic ground state as a result of spin glass - like state for compositions in the range 0.6≤x≤1. No evidence of metamagnetic behaviour was observed from σ(μ₀H) data for all compositions.