Magnetic anisotropy and metal-insulator transition in SrRuO3 thin films at different growth temperatures

Abstract

Magnetic and transport properties of SrRuO3 film grown on SrTiO3 at different substrate temperatures have been investigated. Metallic behavior over the temperature range from 5 to 300 K is observed in the film grown at 750 °C. With a decrease in the growth temperature, a metal-insulator transition occurs for films grown at 700 and 650 °C, with transition temperatures of 15 K and 250 K, respectively, and a complete insulator behavior shows up in the film grown at 600 °C. Correspondingly, out-of–plane (OOP) magnetic anisotropy is gradually weakened, leading to complete magnetic isotropy in the film grown at 600 °C. The OOP lattice constant increases from 0.395 nm, for the film grown at 750 °C, up to 0.403 nm for the film grown at 600 °C. The correlation between the magnetic properties, transport properties, and the lattice constants indicates that the magnetic anisotropy and the metal-insulator transition (or insulator behavior) are caused mainly by strain in the SRO films, with correspondingly larger strain in films grown at lower temperatures.