Coexistence of ferromagnetism and charge ordering in Pr0.5Ca0.5Mn1-xCrxO3

Magnetotransport and magnetization measurements of the Cr-doped manganites Pr0.5Ca0.5Mn1-xCrxO3 (x = 0.03, 0.05) show several anomalous features: larg e magnetic field induced magnetic moments and negative magnetoresistance (M R) with hysteresis, strong deviation of susceptibility from Curie-Weiss law below 240 K in the paramagnetic insulating phase, large differences betwee n zero field cooled and field cooled magnetization and hysteresis in MR and magnetization in the ferromagnetic metallic phase. On the basis of magneti c measurements we suggest that Cr3+ replaces Mn3+ with opposite spin. In ag reement with our magnetic and transport measurements, we show that charge o rdering coexists with ferromagnetism using electron microscopy. Electron mi croscopy work together with susceptibility data suggests that charge and or bital ordering occur at different temperatures. (C) 2000 Elsevier Science L td. All rights reserved.