Anomalous magnetotransport in SrRuO₃ films: A crossover from Fermi-liquid to non-Fermi-liquid behavior

The crystal structures, magnetizations, and magnetotransport properties of SrRuO₃ (SRO) films grown on SrTiO₃ (STO) substrates are studied. The crystal structures of SRO films show a [110]-oriented and a [010]-oriented epitaxially growth for films deposited on the STO(001) and STO(110) substrates, respectively. The low-temperature magnetization follows the Bloch law both for the SRO[110]_oriented and SRO[010]_oriented films, while the magnetization near T_C follows the scaling law, M∝(T_C−T)^α, with α=0.43 and 0.34 for SRO[110]_oriented and SRO[010]_oriented films, respectively, indicating the nature of magnetic anisotropy in SRO. Furthermore, a crossover from a T² to a T^1.5 temperature dependence of resistivity corresponding to the Fermi-liquid to non-Fermi-liquid crossover at around 30–40 K has been observed both in the SRO[110]_oriented and SRO[010]_oriented films. In the paramagnetic regime, the magnetoresistance shows a strong H² dependence at the low-field region. These results will be discussed within existing theoretical frames and lead to the conclusion that the fluctuation-induced strongly correlative electrons dominate the non-Fermi-liquid transport properties from the ferromagnetic regime to the paramagnetic regime.