Effect of B-Site Order-Disorder in the Structure and Magnetism of the New Perovskite Family LaMnB'O with B' = Ti, Zr, and Hf.

In this work, we report the synthesis as well as the structural and magnetic characterization of the three perovskites LaMnB'O (B' = Ti, Zr, and Hf). Interestingly, only LaMnTiO crystallizes in the monoclinic double perovskite space group 2/, with a complete rocksalt order of the B-site cations, whereas LaMnZrO and LaMnHfO crystallize in the orthorhombic simple perovskite space group , with complete disorder in the B site. Moreover, the magnetic susceptibility at low temperatures shows clear antiferromagnetic transitions below 10 K for the three compounds, but only the Ti-based perovskite has long-range magnetic ordering.