Phase transitions and conductivity anomalies in solid solutions of VO2 with TiO2, NbO2, and MoO2

The solid solutions V1−x Ti x O2 (0·02<-x<-0·4) which are monoclinic at room temperature (with the monoclinicity decreasing with increasing x) transform to rutile structures at Tt . The Tt , H as well as the conductivity jump (at Tt ) decrease with increase in x. Incorporation of 2 at.% of Nb (or Mo) lowers the Tt of VO2 considerably, while 10% Nb stabilizes the high-temperature rutile structure. The high temperature rutile phases of all the solid solutions show semiconducting behavior indicating that the conductivity anomalies correspond to semiconductor-semiconductor transitions.