Colossal elastoresistance and strain effects on phase-separated Pr0.5Sr0.5MnO3 films

Abstract

We have studied the electrically tunable strain effects on phase-separated Pr0.5Sr0.5MnO3 films epitaxially grown on ferroelectric 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (001) substrates. Upon cooling, the film shows a ferromagnetic metal to antiferromagnetic insulator (FMM-AFI) transition at low temperature. Such a transition is depressed and finally disappears in electrical properties with increasing electric field applied on the substrate. Under an electric field of 6 kV/cm, a large reversible resistance drop (~85%) as well as an enhancement of magnetization is achieved. In situ X-ray diffraction indicates that the substrate-induced strain plays a crucial role in determining the properties in the film by tuning the phase competition between the ferromagnetic metallic and antiferromagnetic insulating state. The FMM-AFI transition in the film is demonstrated to be originated from a large biaxial strain. With decreasing strain, the FMM state is enhanced, leading to a colossal elastoresistance.