Magnetic-history-dependent nanostructural and resistivity changes in Pr0.5Ca0.5Mn0.98Cr0.02O3

We show that nanostructure and resistivity of Pr0.5Ca0.5Mn0.98Cr0.02O3 are sensitive to whether the sample is zero-field-cooled (ZFC) or field-cooled (FC) either in the “self-magnetic field (H≈2 T)” of the electron microscope or under the external magnetic field of 2 T. FC resistivity at H=2 T is lower than ZFC values below 140 K. The average value of the charge-orbital modulation vector (q=0.44) of the FC crystallites is lower than that of the ZFC crystallites (q=0.48) and the FC crystallites exhibit numerous defects like discommensuration, dislocations, and regions with loss of superstructures compared to the ZFC crystallites.