Magnetoresistance Anisotropy and Anomalous Hall Effect in Sr₃Ru₂O₇

We report on the transport properties of hybrid molecular beam epitaxy-grown thin films of the bilayer perovskite Sr₃Ru₂O₇. Consistent with prior observations, the films undergo a low-temperature metamagnetic transition as evidenced by maxima in the magnetoresistance at magnetic fields near 8 T and 5 T with the magnetic field applied out-of-plane and in-plane, respectively. A striking anisotropy in the magnetoresistance is observed with the magnetic field oriented in-plane. Positive magnetoresistance is observed at low fields when the current is transverse to the magnetic field, while the magnetoresistance is negative with the current parallel to the field. This anisotropy is accompanied by an anomalous signal in the Hall effect, which persists to temperatures as high as 150 K. These observations are suggestive of previously unreported phenomena arising from the interplay of the band structure and complex nature of the magnetism in Sr₃Ru₂O₇.