https://doi.org/10.1140/epjb/e20020022
Electronic structure and metal-insulator transition in SrTi1-xRuxO3
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
We studied the changes in the electronic structure of SrTi1-xRuxO3 across the metal-insulator transition. The parent compound, SrTiO3, is a well known diamagnetic insulator; whereas the doped compound, SrTi1-xRuxO3, becomes a ferromagnetic metal above xC=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 SrTi1-xRuxO3 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.
PACS: 79.60.Bm – Clean metal, semiconductor, and insulator surfaces / 78.70.Dm – X-ray absorption / 71.30.+h – Metal-insulator transitions and other electronic transitions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002