Electron degeneracy and intrinsic magnetic properties of epitaxial Nb:SrTiO${}_3$ thin-films controlled by defects

Abstract

We report thermoelectric power experiments in e-doped thin films of SrTiO${}_3$ (STO) which demonstrate that the electronic band degeneracy can be lifted through defect management during growth. We show that even small amounts of cationic vacancies, combined with epitaxial stress, produce a homogeneous tetragonal distortion of the films, resulting in a Kondo-like resistance upturn at low temperature, large anisotropic magnetoresistance, and non-linear Hall effect. Ab-initio calculations confirm a different occupation of each band depending on the degree of tetragonal distortion. The phenomenology reported in this paper for tetragonally distorted e-doped STO thin films, is similarto that observed in LaAlO${}_3$/STO interfaces and magnetic STO quantum wells.

5 pages, 5 figures

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• Magnetic effects at the interface between nonmagnetic oxides
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Electronic structure of CrN: A comparison between different exchange correlation potentials

Cited by in corpus (6)

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• Ferromagnetic and insulating behavior of LaCoO3 films grown on a (001) SrTiO3 substrate. A simple ionic picture explained ab initio
• Ab initio study of the strain dependence of thermopower in electron-doped SrTiO${}_3$
• Tuning oxygen vacancy diffusion through strain in SrTiO${}_3$ thin films