Magnetic and transport properties of Na doped SrRuO3 and CaRuO3

Abstract

The magnetic susceptibility χ(T) (2≤T≤400 K) and electrical resistivity ρ(T) (2≤T≤300 K) of undoped and Na doped SrRuO3 and CaRuO3 single crystals were measured. These two perovskites are orthorhombic with space group Pbnm. While both of the undoped systems exhibit metallic conductivity, SrRuO3 is ferromagnetic with Tc≤160 K, but CaRuO3 is paramagnetic. When a small concentration of Na (≤12%) replaces Sr in the structure, SrRuO3 becomes an insulator with a depressed ferromagnetic response. In contrast, Na doped CaRuO3 (≤5%) remains metallic with the appearance of antiferromagnetism below 70 K. The dramatic changes in magnetic and transport properties resulting from Na replacement of Sr and Ca reflects the very subtle differences driving the magnetism in SrRuO3 and CaRuO3.