Metal-insulator transition induced in SrTi_{1-x}V_xO_3 thin films

TL;DR

This study investigates the metal-insulator transition in SrTi_{1-x}V_xO_3 thin films, revealing a temperature-driven transition at x=0.67 and analyzing underlying mechanisms like electron correlation and localization.

Contribution

It provides experimental evidence of a tunable MIT in SrTi_{1-x}V_xO_3 thin films and discusses the mechanisms involved, which is novel for this material system.

Findings

MIT at 95 K for x=0.67

Films with x>0.67 are metallic with T^2 resistivity

Insulating films follow variable range hopping model

Abstract

Epitaxial SrTi1-xVxO3 thin films with thicknesses of ~16 nm were grown on (001)-oriented LSAT substrates using the pulsed electron-beam deposition technique. The transport study revealed a temperature driven metal-insulator transition (MIT) at 95 K for the film with x = 0.67. The films with higher vanadium concentration (x > 0.67) were metallic, and the electrical resistivity followed the T^2 law corresponding to a Fermi liquid system. In the insulating region of x < 0.67, the temperature dependence of electrical resistivity for the x = 0.5 and 0.33 films can be scaled with the variable range hopping model. The possible mechanisms behind the observed MIT were discussed, including the effects of electron correlation, lattice distortion and Anderson localization.