Insulator-to-metal transition in (R,Ca)VO3

We have carried out a comprehensive study of the transport and thermodynamic properties of R(1-x)Ca(x)VO(3) (R=Pr, Sm, and Y), obtaining detailed information on the nature of the insulator-metal transition induced by Ca doping. The behavior of the electronic term of the specific heat as a function of doping indicates that the transition is achieved by the use of band-filling control. We find that disorder plays an important role in the transition, which is manifested by weak localization effects in the vicinity of the critical doping level. The metallic state in all three materials is characterized by the presence of strong electron correlations.