Ferromagnetism stabilization of ultrathin SrRuO3 films: Thickness-dependent physical properties

Ultrathin films of SrRuO3 (SRO) have been grown on SrTiO3 (001) substrates to study thickness-dependent physical properties. We have revealed the existence of two critical film thicknesses where a metal-insulator transition occurs at a film thickness of 4–6 ML (monolayer) and the value of Curie temperature saturates at about 15 ML. The electrical and magnetic properties are well correlated with the thickness-dependent evolution of surface morphology of the ultrathin SRO films. These experimental results suggest the importance of the disorder associated with the unique growth mode transition in SRO films.