Synthesis, structure analysis and magnetic properties of Ca2TiMnO6 oxides

Ca2TiMnO6 compounds were synthesized by the conventional solid-state reaction in air. The crystal structure and magnetic properties were investigated. Characterization of X-ray diffractions and the refinement analysis confirmed the orthorhombic (space group Pbnm) structure of Ca2TiMnO6 at room temperature. Magnetic measurements reveal that the double perovskite Ca2TiMnO6 has antiferromagnetic interactions at low temperature and a paramagnetic order above 40 K. According to the Curie–Weiss fitting at high temperature, the Neel constant θp and experimental efficient moment μeff was estimated to be about −161.98 K and 4.91 μB, respectively. The theoretical efficient moment was calculated to be 3.87 μB. The XPS analysis indicates that the difference between experimental and theoretical efficient moment caused by the mixed valence state of Mn in Ca2TiMnO6. The temperature dependence of coercivity field shows a soft magnetic property in Ca2TiMnO6 oxides. The mechanism of the low temperature anomaly which was appeared in magnetization curve was discussed in detail.