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

•The two series of samples of perovskite manganites La0.95T0.05CrxMn1−xO3 (T = Ca, Sr; 0.00 ≤  x ≤ 0.30) have been prepared, which were thermal treated at different temperature.•The Curie temperature of the two series of samples first increased and then decreased with increasing Cr content (x).•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.