SINGLE-CRYSTAL NEUTRON-DIFFRACTION STUDY OF A STRUCTURAL PHASE-TRANSITION INDUCED BY A MAGNETIC-FIELD IN LA1-XSRXMNO3

The compound La1-xSrxMnO3 undergoes structural and magnetic phase tran sitions as a function of temperature and pressure. The temperature at which the structural phase transition from a high-temperature rhombohe dral phase to a low-temperature orthorhombic phase takes place is very sensitive to the level of doping (x) and pressure, the magnetic trans ition temperature to a ferromagnetically ordered state less so. Recent magnetostriction and resistivity measurements have suggested that the structural transition may also be driven by the application of a magn etic field. We have performed single-crystal neutron-diffraction exper iments which confirm that by carefully controlling the level of doping the structural phase transition can be induced at constant temperatur e by application of a magnetic field.