Ru doping of the A-type antiferromagnet Pr0.5Sr0.5MnO3: Conversion to a metallic ferromagnet

Abstract

The doping of Mn sites of the A-type antiferromagnet ${\mathrm{Pr}}_{\mathrm{0.5}}{\mathrm{Sr}}_{\mathrm{0.5}}{\mathrm{MnO}}_{\mathrm{3}}$ with ruthenium shows that ferromagnetism and metallicity are induced similarly to the doping of the CE-type phases ${\mathrm{Ln}}_{\mathrm{0.5}}{\mathrm{Ca}}_{\mathrm{0.5}}{\mathrm{MnO}}_{\mathrm{3}}.$ This effect, similar to the Cr doping, differs from the latter by the fact that $T_C{\mathrm{=T}}_{\mathrm{IM}}$ increases significantly with the Ru level. The different behaviors of Ru and Cr doped ${\mathrm{Pr}}_{\mathrm{0.5}}{\mathrm{Sr}}_{\mathrm{0.5}}{\mathrm{MnO}}_{\mathrm{3}}$ samples are interpreted on the basis of two factors, ferromagnetic superexchange introduced by the magnetic dopants, and valency effect which contributes to increase the ${\mathrm{Mn}}^{\mathrm{3+}}$ content for Ru(IV) and Ru(V) and does the opposite for Cr(III).