Magnetization reversal and chemical pressure effect in the electron-doped manganite CaMn0.95Sb0.05O3

We have demonstrated the effect of Sr substitution on the temperature-dependent magnetization reversal in the electron-doped manganite CaMn0.95Sb0.05O3. X-ray photoemission spectroscopy reveals the substitution of the Sb ion with its valence of 5+ at a Mn4+ site, resulting in one eg-electron doping, which is consistent with the negative Seebeck coefficient previously reported. For the (Ca1−ySry)Mn0.95Sb0.05O3 system, anomalously-diamagnetic behaviors are observed for y ≤ 15% in the weak-field-cooled magnetization. For Sr contents beyond 15%, the behavior of the negative magnetization disappears. We believe that the local lattice distortion due to Sb substitution causes a tilting of the Jahn-Teller active Mn3+O6 octahedron and stabilizes the canted spin state in a direction opposite that of applied field through the Dzyaloshinsky-Moriya interaction, thus contributing to the diamagnetic response.