Magnetic Field-Induced Insulator-to-Metal Transition in Perovskite Manganites Eu₁-xSr_xMnO₃

Abstract

The perovskite manganites Eu_1-xSr_xMnO₃ are semiconductors although they exhibit ferromagnetic behavior around x=0.40. There is no evidence that charge ordering occurs. In an applied magnetic field of 15, kOe, however, the specimens with x=0.40 and 0.45 become the metallic conductors below their respective Curie temperatures of 75, K and 80, K. This magnetic field-induced insulator-to-metal transition leads a change in the resistivity exceeding 10⁶ at 12, K. The transition is irreversible with respect to the magnetic field. The possibility of a field-induced phase transition having a lower symmetry than that at room temperature (orthorhombic) is in consideration.