In situ dynamical control of the strain and magnetoresistance of La0.7Ca0.15Sr0.15MnO3 thin films using the magnetostriction of Terfenol-D alloy

We fabricated a magnetoelectric laminate structure consisting of a magnetostrictive Tb0.3Dy0.7Fe1.92 (Terfenol-D) plate bonded to a La0.7Ca0.15Sr0.15MnO3 (LCSMO)/0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN–PT) structure where a LCSMO film was epitaxially grown on a PMN–PT single crystal substrate. When a dc magnetic field is applied perpendicular to the film plane, the magnetoresistance of the LCSMO film in the paramagnetic (ferromagnetic) state for the LCSMO/PMN–PT/Terfenol-D structure is larger (smaller) than that for the LCSMO/PMN–PT structure without Terfenol-D. These effects are caused by the magnetostriction-induced in-plane compressive strain in the Terfenol-D, which are transferred to the PMN–PT substrate, leading to a reduction in the in-plane tensile strain of the epitaxial LCSMO film and thereby modifying the magnetoresistance of the film.

Research highlights
► In situ dynamic change of the strain and magnetoresistance using magnetostriction effect.
► Opposite effects of the induced strain on the magnetoresistance.
► A new method to study the intrinsic strain effects of complex oxide thin film.