Magnetostriction study of structural and magnetic transitions in La1-xSrxMnO3 (0.1 < x < 0.2)

Magnetostriction measurements were performed for stoichiometric La1-xSrxMnO 3 samples with x = 0.11, 0.13, and 0.165 in magnetic fields to 12 T. By com bining temperature and magnetic field dependent magnetostriction data with magnetization and resistivity results, the complex relationship between str uctural and physical properties was clarified. In the paramagnetic phase, l arge magnetic fields suppress a transition near x = 0.13 from a structure w ith disordered Jahn-Teller (JT) orbital ordering (O-*) to a structure with large coherent JT orbital ordering (O-'), and near x = 0.165 remove a trans ition from a structure with no coherent JT orbital ordering (R) to O*. The reentrant structural transition from O' to O* appears between ferromagnetic and spin-canting transitions for x = 0.11 and 0.13; temperatures of all tr ansitions increase with magnetic field. The low temperature structural O* t o O' transition in the ferromagnetic phase for x = 0.165 remains unchanged by application of an external magnetic field. (C) 2000 American Institute o f Physics. [S0021-8979(00)00906-3].