Anisotropic physical properties of the charge and orbital ordering phase in Bi0.53Sr0.47MnO3Bi0.53Sr0.47MnO3

Anisotropic properties of a single-domain crystal Bi1-xSrxMnO3Bi1-xSrxMnO3 with x=0.47x=0.47 were investigated. Temperature dependence of resistivity and magnetization show an anomaly which is accompanied by a hysteresis at 400–550K and a kink near 600 K. The hysteresis and the kink may be attributed to the charge order–disorder transition accompanied with orbital commensurate–incommensurate phenomenon, and to the orbital order–disorder transition, respectively. Magnetization measurements show an antiferromagnetic transition near 150 K. Below 150 K, the magnetization for a magnetic field in the ab  -plane is larger than that along the cc-axis. This magnetic anisotropy indicates that the Mn spin moments direct to the cc-axis. In the charge ordering phase, anisotropy of the resistivity is approximately ρab/ρc≃10ρab/ρc≃10. This indicates that egeg electrons on excess Mn3+Mn3+ ions can move more easily along the cc-axis than in ab-plane.