Negative magnetization and the tunable exchange bias field in LaCr0.8Mn0.2O3

• Substitution of 20 at% of Mn in the Cr site of antiferromagnetic LaCrO3 leads to an interesting phenomenon of magnetization reversal (negative magnetization) with the maximum magnetic compensation (M=0) temperature, and Tcomp =147 K. In addition to that the sample exhibits tunable exchange bias phenomenon at T• A low temperature transition at around 50 K along with a reentrant positive magnetization is also observed.
• The observed negative magnetization is explained by considering the paramagnetic moment of doped Mn ions under the influence of negative internal field.
• The magnitude of exchange bias field is found to increase with decrease in cooling field. The origin of exchange bias field is explained in terms of anisotropic exchange interaction between the canted ferromagnetic component of Cr3+ ions and the paramagnetic component of Mn3+ ions under the negative internal field.

Manganese substituted Lanthanum chromite LaCr0.8Mn0.2O3 exhibits negative magnetization with decrease in temperature under the field cooled (FC) condition for the applied field H≤2000 Oe. The maximum magnetic compensation temperature, (Tcomp) was 147 K. A reentrant positive magnetization was observed at T≤50 K due to low temperature transition. The negative magnetization is explained by considering the paramagnetic moment of Mn ions under the influence of negative internal field. Measurement of magnetic hysteresis loops under FC condition shows the presence of exchange bias field at T