Structural, magnetic, and transport properties in La_(0.7)Ca_(0.3)Mn_(1-x)Sc_(x)O_(3)

摘要

Structural, magnetic, and transport properties of polycrystalline La_(0.7)Ca_(0.3)Mn_(1-x)Sc_(x)O_(3) have been experimentally investigated. Single-phase samples are obtained in the range 0≤x≤0.25 by the soft chemical synthesis route. The substitution of Sc~(3+) at the Mn site results in reductions in the Curie temperature T_(c) and in the magnetic moment per Mn ion. The T_(c) transition temperature becomes broader with x, and the magnetic spontaneous state has changed into a cluster glass state for the sample of x=0.1. In addition, great enhancement in resistance and magnetoresistance effect is observed in the Sc-doped samples. In our case the notable doping effects can be mainly ascribed to the variation in the Mn~(3+)-O~(2-)-Mn~(4+) network and to the magnetic disorder caused by the presence of the large and nonmagnetic Sc~(3+) ions in the Mn sublattice.