Comparison of the magnetic properties of isoelectronic Sr-x(Na0.5La0.5)(1-x)RuO3 and SrxCa1-xRuO3 perovskites

The solid solution Sr-x(Na0.5La0.5)(1-x)RuO3 (0 less than or equal to x less than or equal to 1) is reported, and its structural, electronic, and magnetic properties are compared to isoelectronic SrxCa1-xRuO3. The suppression of ferromagnetic interactions in SrxCa1-xRuO3 has frequently been attributed to the orthorhombic structural distortion, either through the crossover to classical antiferromagnetic interactions, or to a nearly ferromagnetic metal. Comparison of the magnetic properties of Sr-x(Na0.5La0.5)(1-x)RuO3 to SrxCa1-xRuO3, however, shows that there is a much faster suppression of ferromagnetic interactions in the former case. Neither orthorhombic distortion nor cation size disorder can explain the observed difference. Instead, the difference may be attributed to charge disorder an the site, which affects the local environment of Ru atoms greatly and leads to the faster suppression of the long-rant ferromagnetic state.