Anomalous magnetotransport in Pr0.5Ca0.5Mn0.99Cr0.01O3

Pr0.5Ca0.5Mn0.99Cr0.01O3 shows several anomalous properties: Field-cooled ( FC) resistivity at 10 K is several orders of magnitude lower than the zero- field cooled (ZFC) value, magnetoresistance isotherm at 125 K is asymmetric about the origin (H = 0 T) and resistivity and magnetization are hystereti c between field cooling and field warming. No clear difference between ZFC and FC magnetization up to 5 T was found. We suggest that nanometric-size f erromagnetic clusters coexist with the charge-ordered antiferromagnetic mat rix in H = 0 T and the matrix breaks into domains upon field cooling which leads to low resistivity. (C) 2000 American Institute of Physics. [S0003-69 51(00)03536-1].