Comparison of the magnetic properties of isoelectronicSrx(Na0.5La0.5)1−xRuO3andSrxCa1−xRuO3perovskites

Abstract

The solid solution ${\mathrm{Sr}}_{x}({\mathrm{Na}}_{0.5}{\mathrm{La}}_{0.5}{)}_{1\ensuremath{-}x}{\mathrm{RuO}}_{3}$ $(0<~x<~1)$ is reported, and its structural, electronic, and magnetic properties are compared to isoelectronic ${\mathrm{Sr}}_{x}{\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{RuO}}_{3}.$ The suppression of ferromagnetic interactions in ${\mathrm{Sr}}_{x}{\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{RuO}}_{3}$ 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 ${\mathrm{Sr}}_{x}({\mathrm{Na}}_{0.5}{\mathrm{La}}_{0.5}{)}_{1\ensuremath{-}x}{\mathrm{RuO}}_{3}$ to ${\mathrm{Sr}}_{x}{\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{RuO}}_{3},$ 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 on the A site, which affects the local environment of Ru atoms greatly and leads to the faster suppression of the long-range ferromagnetic state.