Structural and magnetic properties of Mn\u3csub\u3e2 +δ\u3c/sub\u3eTiSn

The structural and magnetic properties of Mn2 +δTiSn prepared by arc melting and annealing have been investigated. Structural studies show that the compound crystallizes in the hexagonal Ni3Sn-type structure with a=5.70Å and c=4.55Å . The phase stability of Mn2TiSn in the hexagonal structure is supported by the first-principle electronic structure calculations where the total energy per unit-cell volume in the hexagonal structure is smaller than that in the cubic structure. Field and temperature dependence of magnetization show that the sample is magnetically ordered with a Curie temperature around 400 K. The anisotropy energy calculated from the high-field data is 4.0×105 ergs/cm3 at 300K but increases by a factor of two (8.6×105 ergs/cm3) as temperature decreases to 10 K. The observed magnetic properties are explained as the consequences of competing ferromagnetic and antiferromagnetic interactions between different magnetic sublattices