Cation distribution and magnetic properties of titanomagnetites Fe3−xTixO4 (0≤x<1)

Abstract

Magnetization measurements are presented for the ${\mathrm{Fe}}_{3\mathrm{-}\mathit{x}}$ ${\mathrm{Ti}}_{\mathit{x}}$ ${\mathrm{O}}_4$ series in the range 0≤x<1. A new model of ${\mathrm{Fe}}^{3+\mathrm{-}}$ ${\mathrm{Fe}}^{2+}$ cation distribution is proposed based on saturation-magnetization data. A tilting of the easy magnetization axis away from the [001] direction was encountered at temperatures approaching 4.2 K for the titanium-rich specimens. Anomalies in the hysteresis parameter in the temperature range 40–100 K are reported. A distribution of ${\mathrm{Fe}}^{2+}$, ${\mathrm{Fe}}^{3+}$, and ${\mathrm{Ti}}^{4+}$ ions on tetrahedral and octahedral sites is proposed on the basis of saturation magnetization measurements, which differs to some extent from earlier models published in the literature.