Selective dilution and magnetic properties of La0.7Sr0.3Mn1-xM’xO3 (M’=Al,Ti)

The magnetic lattice of mixed-valence Mn ions in ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ is selectively diluted by the partial substitution of Mn by Al or Ti. The ferromagnetic-paramagnetic transition temperature ${T}_{\mathrm{c}}$ and the saturation moment ${M}_{\mathrm{s}}$ decreases with substitution in both series. The volume fraction of the nonferromagnetic phases evolves nonlinearly with the substitution concentration and faster than theoretically expected. By presenting the data in terms of selective dilution, the reduction of ${T}_{\mathrm{c}}$ is found to be scaled by the relative ionic concentration and is consistent with a prediction derived from molecular-field theory.