Effect of Mn-site Si substitution on magnetic, transport properties and colossal magnetoresistance in La2/3Ca1/3Mn1−xSixO3 (x=0.05–0.25) system

A series of single phased polycrystalline samples of La2/3Ca1/3Mn1−xSixO3 ( x = 0.05 – 0.25 ) system have been successfully prepared. The magnetic, transport properties and magnetoresistance effect of this series have been systematically investigated. The Curie temperature T C decreases gradually with increasing Si content x . The magnetization M is suppressed and the PM–FM transition is broadened with increasing x . The saturation magnetic moments M s both from experimental and spin-only theoretical estimations decrease gradually with increasing x . The Si substituted on Mn site introduces extraordinary electrical transport properties, characterized by the double peaks and low temperature minimum behavior. Moreover, the substitution of Si indeed enhances the colossal magnetoresistance (CMR) effect in the perovskite manganite materials.