Magnetic field effect on quantum corrections to the low-temperature conductivity in metallic perovskite oxides

The transport and magnetotransport properties of the metallic and ferromagnetic SrRuO3 SRO and the metallic and paramagnetic LaNiO3 LNO epitaxial thin films have been investigated in fields up to 55 T at temperatures down to 1.8 K. At low temperatures both samples display a well-defined resistivity minimum. We argue that this behavior is due to the increasing relevance of quantum corrections to the conductivity QCC as temperature is lowered; this effect being particularly relevant in these oxides due to their short mean free path. However, it is not straightforward to discriminate between contributions of weak localization and renormalization of electron-electron interactions to the QCC through temperature dependence alone. We have taken advantage of the distinct effect of a magnetic field on both mechanisms to demonstrate that in ferromagnetic SRO the weak-localization contribution is suppressed by the large internal field leaving only renormalized electron-electron interactions, whereas in the nonmagnetic LNO thin films the weak-localization term is relevant.