The effect of Ga doping in Nd_(0.7)Sr_(0.3)MnO_3 system

摘要

The structural, magnetic, and transport properties of the polycrystalline-doped systems Nd_(0.7)Sr_(0.3)Mn(1-x)Ga_xO_3(0 ≤ x ≤ 0.20) were investigated. For the parent and low-doped samples (0 ≤ x ≤ 0.11), they show a long-range ferromagnetic state below T_C and the Griffiths singularity above T_C. When x further exceeds 0.12, a transition from the metal ferromagnetic to the insulating cluster-spin-glass state as a function of Ga doping takes places at low temperatures, x = 0.12 is just a critical point x_c transforming from the Griffiths singularity to the cluster-spin-glass state.