Electron-electron interaction and weak localization effects in badly metallic SrRuO3

Abstract

We report on the effect of light ion irradiation on the low-temperature electrical resistivity of ferromagnetic SrRuO3 thin films. Fresh samples displayed a ferromagnetic transition at Tc∼160K, good metallic behavior (ρ(300K)∼400μΩ cm, dρ/dT > 0) at room temperature, and the low-temperature upturn in the electrical resistivity commonly found in SrRuO3. Badly metallic films, displaying high values of the electrical resistivity (O(1000μΩ cm)) and incipient nonmetallic behavior (dρ/dT < 0) at low temperature, were obtained by He+ irradiation. For high enough irradiation doses, these samples did not show magnetic order down to the base temperature of our experiments. The temperature dependence of the electrical conductivity of virgin and irradiated samples is discussed in terms of a weak localization contribution plus a large electron-electron interaction term. The magnitude of the e--e- contribution reflects the enhancement of strong electron correlations in SrRuO3 due to disorder. © 2001 The American Physical Society.