Unique magnetic properties of perovskite manganites La0.95T0.05CrxMn1−xO3 (T = Ca, Sr)

Powder samples of La0.95T0.05CrxMn1−xO3 (T = Ca or Sr, 0.00 ≤ x ≤ 0.30), two series of ABO3 perovskite manganites, were synthesized using the sol-gel method. X-ray diffraction analysis showed that all the samples had a single ABO3 perovskite phase with space group R3‾c. Unique magnetic properties were obtained for the oxides: (i) the Curie temperature of each series of samples first increased and then decreased with increasing Cr content (x); (ii) the average molecular magnetic moment reached the maximum value when x = 0.08 for the Ca-doped samples, but it monotonically decreased with increasing x for the Sr-doped samples. This behavior was explained using an O 2p itinerant-electron model for magnetic oxides.