Cr-doping-induced phase separation and MR effect in the manganite Pr_(0.5)Ca_(0.5)Mn_(1-x)Cr_xO_3 system

摘要

Systematic study on magnetic and electrical transport properties has been performed on the Cr-doped Pr_(0.5)Ca_(0.5)Mn_(1-x)Cr_xO_3 (x=0, 0.03, 0.05, 0.07, 0.10) system. The results show that Cr-doping leads to melting of the charge ordering and induces phase separation. For the sample x=0.10, reentrant spin glass behavior is observed and the slowing down model is applicable. The reentrant spin glass behavior and the phase coexistence of charge ordering (CO) and the ferromagnetic metal phase (FMM) are responsible for the changing magnetoresistance effect of the system. The phase separation or coexistence of the CO and FM phase induced by Cr-doping plays an important role in the low temperature properties for the system.