Magnetic Properties of Orthorhombic Perovskite Ho_1−xLa_xMnO₃

Single phase orthorhombic perovskite Ho_1−xLa_xMnO₃ (x=0.1, 0.15) compounds are successfully synthesized by using a sol−gel method. We find that the orthorhombic perovskite structure of HoMoO₃ compound can be stabilized by partial substitution of smaller Ho ion by larger La ion. The magnetic properties of orthorhombic perovskite Ho_1−xLa_xMnO₃ are investigated for the first time. For the x=0.15 sample, a ferromagnetic−like transition is found around T = 130 K, which should correspond to partial FM ordering of Mn³⁺ magnetic moments. The partial substitution of Ho by La causes a switch of magnetic state of Mn³⁺ moments from AFM order to FM-like order. Our study indicates that La doping has significant influence on the magnetic structures of Mn ions.