Distinguishable reentrant spin-glass behavior induced by the frustration of exchange interaction in phase-separatedSm0.5(Ca,Sr)0.5MnO3systems

Abstract

In order to understand the relationship between the stability of the charge-ordered state and the low-temperature phase competition, the magnetic and electrical properties are systemically investigated for half-doped ${\mathrm{Sm}}_{0.5}{A}_{0.5}\mathrm{Mn}{\mathrm{O}}_{3}$ systems with a dissimilar average $A$-site cationic radius of Ca and Sr, which induces a complete different magnetic ordering and the complex coexistence of magnetic phases at the lower temperature. Some abnormal phenomena are observed in both systems. The frequency dependence of ac magnetization and the bifurcation between zero-field-cooled and field-cooled magnetization curves indicate the reentrant spin-glass behavior in both oxides, which may be induced by the frustration of the ferromagnetic double-exchange interaction and antiferromagnetic superexchange interaction. A long-time relaxation of magnetization is possibly due to the cluster-type and traditional reentrant spin-glass transition. The difference between the behaviors of these two series proves the existence of two types of reentrant spin glass.