A structural phase transition induced by an external magnetic field

A VAST number of compounds are known that exhibit structure transformations in response to changes in temperature, pressure and/or composition. One such example is the family of perovskites, La1-xSrxMnO33 for a limited range of compositions (x), they undergo a structural phase transition from an orthorhombic to a rhombohedral form with increasing temperature1, 2. These compounds are also ferromagnetic, a property that arises from coupling between the charge carriers and localized spin moments of the manganese ions3–7. Here we show that, through careful tuning of the composition, the local spin moments and the charge carriers can in turn be coupled strongly to changes in the structure. For x = 0.170, the crystal structure of the compound can be switched—reversibly or irreversibly, depending on the temperature—by application of an external magnetic field.