Magnetic and transport properties of epitaxial films of SrRuO 3 in the ultrathin limit

We measured ultrathin epitaxial films of the itinerant ferromagnet SrRuO3 to study effects of decreasing film thickness on transport and magnetic properties. We find that the resistivity ratio decreases, the ferromagnetic phase transition occurs at a lower Curie temperature, and the easy axis of magnetization rotates toward a more perpendicular orientation. We discuss possible interpretations of the observed behavior.