Gate tuning of anomalous Hall effect in ferromagnetic metal SrRuO3

The electric field effect on ferromagnetism offers a new dimension in the recent advancement of spintronics. We report on the gate control of transport properties in thin films of oxide-based ferromagnetic metal, SrRuO3. An electric double layer transistor configuration was utilized with an ionic liquid dielectric to apply a strong electric field on a SrRuO3 thin film of 5 monolayers in thickness. The application of gate voltage induced a clear electroresistance effect, despite a considerably-large initial carrier density of the order of 10(22) cm(-3). Furthermore, we found that the gate modulation of the anomalous Hall conductivity sigma(xy), which was as large as similar to +/- 40% at low temperatures, was about three times larger than that of the longitudinal conductivity sigma(xx). The variation of sigma(xy) is characterized by the power-law scaling relation with sigma(xx), which is widely observed in a bad metal regime of the charge transport. (C) 2014 AIP Publishing LLC.