Semiconductor-metal transition in Ti3O5

Ti3O5 shows a first-order phase transition from the monoclinic structure to the pseudobrookite structure at 448°K, at which temperature a magnetic susceptibility anomaly has been reported earlier in the literature. There is an electrical conductivity discontinuity accompanying the phase transition. Incorporation of Fe stabilizes the high-temperature phase of Ti3O5; while with 2% Fe the transition temperature and enthalpy change are lowered, with 5% Fe there is no transition. Mössbauer spectra of 2% Fe-doped Ti3O5 are similar below and above the transition temperature and show no evidence for magnetic ordering in the low-temperature phase. These results are compared to the VO2 transition.