Metamagnetic Phase Transitions in FeTiO₃

Abstract

Magnetic susceptibilities and magnetization isotherms have been measured for single crystal FeTiO 3 . The susceptibility parallcl to the c -axis has a large and sharp peak at T N =58.0±0.3 K, while the perpendicular susceptibility is almost independent of temperature below T N . Magnetization isotherm at 4.2 K with fields applied along the c -axis exhibits a typical metamagnetic transition at H c =80.3±0.1 kOe, being the first observation of metamagnetism in 3 d transition metal oxides. The transition is of the first order up to about 35 K, above which it is of the second order. The experimental data are well reproduced by molecular field calculations with the best fit parameters of the anisotropy field H A =150 kOe, the ferromagnetic intrasublattice exchange interaction of 2 z 1 J 1 =28.5 K, and the antiferromagnetic intersublattice interaction of 2 z 2 J 2 =-6.67 K.