Magnetization reversal in the Cr-doped manganite Bi0.3Ca0.7Mn0.75Cr0.25O3

Detailed magnetic properties of polycrystalline Bi0.3Ca0.7Mn0.75Cr0.25O3 are investigated. It is observed that this compound exhibits negative magnetization below the compensation temperature (Tcomp) when magnetization–temperature (M–T) curves are measured in a field-cooled mode with low applied fields (H < 1030 Oe). Furthermore, the compound shows a canted-antiferromagnetic transition at 120 K and a peak with positive sign at 98 K. Below 98 K, M decreases with decreasing temperature, passes through a zero value (M = 0) around Tcomp = 78.5 K, and continues to decrease steeply until 5 K. The maximum absolute value of M below Tcomp was about 15 times as large as that above Tcomp. Considering the fact that the observed behavior is similar to that in GdCrO3, the phenomenon of the magnetization reversal in the Cr-doped manganite Bi0.3Ca0.7Mn0.75Cr0.25O3 is suggested to originate from the antiparallel coupling of the Cr3+ moments and the canted Mn3+/4+ moments.

► The MR phenomenon is observed in BCMCO sample in the FC magnetization measurement as the applied field is below 1030 Oe.
► The presence of two components to the magnetic ordering come from the contribution of Mn3+/Mn4+ and Cr3+ moments.
► The MR phenomenon is suggested to stem from the antiparallel coupling of the Cr3+ moments and the canted Mn3+/4+ moments.