Extraordinary Hall effect in Ba1−xSrxRuO3

Abstract

We have investigated the extraordinary Hall effect of Ba1−xSrxRuO3 thin films with x = 1 and 0.8. For x = 1, the extraordinary Hall coefficient (Rs) can be interpreted by the skew scattering mechanism in the paramagnetic region (T > 160 K) and by the combination of the skew and the side-jump scattering mechanisms as Rs = aρ + bρ2 where ρ is the resistivity in the ferromagnetic region above about 60 K. This observation means that the mechanism of the extraordinary Hall effect in the system is basically the same as that of the ordinary ferromagnetic metals. Below 60 K, the extraordinary Hall resistivity ρH shows an anomalous field dependence at intermediate field region. Rs below about 60 K obtained from ρH(H) in higher field region shows an anomalous temperature dependence, which suggests that the coefficients a and b of the skew and the side-jump scatterings are temperature and field dependent. No anomalies both in the temperature and the field dependence below 60 K were observed in the sample with x = 0.8. According to the structural analysis of the samples, we infer that the modulation of the Fermi surface due to the structural change plays an important roll on the anomaly of the extraordinary Hall effect for x = 1.