Low-temperature magnetoresistance in untwinned CaRuO3 films

CaRuO3 is a paramagnetic metal and since its low-temperature resistivity is described by ρ=ρ0+ATα with α∼1.5, it is also considered a non-Fermi liquid (NFL) metal. We report low-temperature magnetoresistance (MR) and Hall effect measurements of untwinned epitaxial films of CaRuO3. The extraordinary Hall effect measurements reveal uniaxial magnetocrystalline anisotropy reflected in anisotropic paramagnetic susceptibility. The MR is positive and data with the magnetic field applied at different angles can be scaled assuming the dependence of the MR on the magnitude of the magnetization. We use this scaling to determine that at 2K the ratio between the susceptibilities along the easy and hard axes is ∼2.9. These results enable the separation between the contribution of the ordinary and the extraordinary Hall effect and the determination that at 2K the charge carriers are holes and their density is ∼2.4x1022cm-3