Regular Article

Calculated Drude weight and optical gap across the metal–insulator transition in the RVO₃ series (R = Sr, Ca, La, Y)

Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba PR, Brazil

^a Present addresses: Institut de Physique, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland and Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland.
^b e-mail: miguel@fisica.ufpr.br

Received: 4 April 2019
Received in final form: 5 June 2019
Published online: 5 August 2019

Abstract

We studied the changes in the optical properties of the RVO₃ series (R = Sr, Ca, La, Y) using band structure calculations. These oxides present a transition from a non-magnetic metallic phase in SrVO₃–CaVO₃, to an antiferromagnetic insulator state in LaVO₃–YVO₃. The standard LDA and GGA approach to DFT fails to reproduce the observed band gap in the LaVO₃–YVO₃ insulating compounds. We show here that the use of the modified Becke-Johnson exchange potential in the calculation of the optical properties solves this problem. In particular, the optical conductivity of the metallic SrVO₃–CaVO₃ oxides exhibits a Drude contribution, whereas the insulating LaVO₃–YVO₃ materials reflects the opening of the optical gap. We also show that the calculated optical conductivity of these materials is in good agreement with previous experimental results.