Eur. Phys. J. B 25, 203-208 (2002)
https://doi.org/10.1140/epjb/e20020022

Electronic structure and metal-insulator transition in SrTi_1-xRu_xO₃

¹ Departamento de Física, Universidade Federal de Paraná, Caixa Postal 19091, 81531-990 Curitiba PR, Brazil
² Instituto de Física de São Carlos, Universidade de São Paulo, Av. Dr. C. Botelho 1465,13560-250 São Carlos SP, Brazil
³ Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806, USA

Corresponding author: ^a miguel@fisica.ufpr.br

Received: 10 September 2001
Published online: 15 January 2002

Abstract

We studied the changes in the electronic structure of SrTi_1-xRu_xO₃ across the metal-insulator transition. The parent compound, SrTiO₃, is a well known diamagnetic insulator; whereas the doped compound, SrTi_1-xRu_xO₃, becomes a ferromagnetic metal above x_C=0.35. The techniques used in the study were photoemission (PES) and O 1s X-ray absorption (XAS) spectroscopy. The experimental spectra were analyzed in terms of band structure and Hubbard model calculations. The PES and XAS spectra of SrTi_1-xRu_xO₃ show the Ru 4d bands growing in the band gap of SrTiO ₃ . The analysis in terms of the Hubbard model indicates that the Ti 3d and Ru 4d bands are mostly decoupled. This suggests that the metal-insulator transition is a percolation transition like that of metals embedded in a rare gas matrix. Electron correlation effects are present in this system, but they do not seem to play a major role in the transition.