Anomalous hall effect with giant hysteresis loop in LaSrMnO|SrRuO superlattices

Shiomi, Yuki*; Handa, Yu*; Kikkawa, Takashi*; Saito, Eiji

We report anomalous Hall effects exhibiting a hysteresis loop as large as about 10 T in a ferromagnetic superlattice comprising LaSrMnO and SrRuO layers. The superlattices grown by pulsed laser deposition exhibit a strong antiferromagnetic interlayer coupling below 110 K, where both LaSrMnO and SrRuO layers show anomalous Hall effects. With increasing magnetic-field strength, the anomalous Hall resistivity in the superlattices changes its sign depending on the magnetization directions of the LaSrMnO and SrRuO layers. As a consequence of competition among the antiferromagnetic interlayer coupling, the Zeeman effect, and magnetic anisotropies, the width of the hysteresis loop in the anomalous Hall resistivity in the superlattices becomes larger than 8 T at 10 K, clearly greater than those observed in LaSrMnO and SrRuO single layer films.