High temperature spin reorientation, magnetization reversal and magnetocaloric effect in 50% Mn substituted polycrystalline ErFeO3

The structural, magnetic and magnetocaloric properties of 50% Mn substituted ErFeO3 are studied by X-ray diffraction, magnetization and specific heat measurements. ErFe05Mn0.5O3 crystallizes in an orthorhombic structure (Pbnm). DC magnetization and specific heat studies point to two magnetic transitions: (i) Fe3+/Mn3+ ordering, T-N similar to 245 K and (ii) spin re-orientation transition, T-SR similar to 218 K. Below T-SR, ErFe05Mn0.5O3 exhibits a reduction in magnetization and coercivity which could be due to a Gamma(4)-Gamma(1) magnetic transition. Interestingly, we have observed a negative magnetization in field cooled curves at lower temperatures under lower applied fields (<50 Oe) as a result of the polarization of paramagnetic Er3+ moments with the internal field created by Mn3+ ordering from the Mn-rich regions. A significant magnetic entropy change (-Delta S-m) of 13.4 J/kg.K is also observed at 9.5 K for an applied field of 7 T.