Stabilization of microcrystal λ-Ti3O5 at room temperature by aluminum-ion doping

λ-Ti3O5 is an intriguing phase-transition material that has been proposed to be metastable and has emerged at room temperature only in the form of nanocrystals. In this work, λ-Ti3O5 was stabilized to room temperature in the form of microcrystals by aluminum (Al)-ion doping. Al entered the Ti3O5 lattice in the substitutional mode, which reduced the threshold temperature (Tc) of the β-λ phase transition in Ti3O5 and maintained a λ-phase Ti3O5 at room temperature. Al doping caused a significant decrease in resistivity of Ti3O5, which corresponds to a semiconductor-metal transition that is induced by Al-ion doping. We have developed a mechanism to fabricate λ-Ti3O5 by ion doping and have provided a fundamental foundation for a more available application of λ-Ti3O5 in smart optoelectronic devices.