Preparation and characterization of FeTiO₃-Fe₂O ₃ solid solution system

The ilmenite-hematite solid-solution, xFeTiO₃-(1-x) α-Fe₂O₃ samples with x=0.7-1.0. were prepared by standard solid state reaction technique in an evaculated quartz tube. The sample pellets were heated at 1200°C for 24 hr, then furnance cooled to room temperature¹. All samples consisted of a single phase of ilmenite structure. Lattice parameters of these samples estimated from the XRD patterns varied linearly with decreasing the Ti concentration on the basis of the Vegard's law. The saturating magnetization at 78 K was obtained at x=0.8 (Fe_1.2Ti_0.8O₃), and the sample with x=0.7 (Fe_1.3Ti_0.7O₃) was ferrimagnetic at room temperature. The carrier type measured by Seebeck coefficient was changed from p-type to n-type at about x=0.78 with decreasing the Ti concentration. Electronic states of Fe and Ti ions in FeTiO₃ seemingly had the characteristic features of Fe²⁺ and Ti⁴⁺ respectively. However the Ti 2p→3p resonant valence band photoemission spectra of FeTiO₃ had a clear density assigned to the Ti 3 d derived states. The small density appeared just below the Fermi edge was intrinsic for the FeTiO₃ crystals because of identical x-ray absorption spectrum at Ti L_2,3 edges between constant initial state and total electron yield mode.