Colossal elastoresistance and strain effects on phase-separated Pr_0.5Sr_0.5MnO₃ films

¹ Physics Department, Zhejiang Normal University - Jinhua 321004, Zhejiang, PRC
² Physics Department, The University of Hong Kong - Pokfulam Road, Hong Kong
³ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences Beijing 100190, PRC

^(a) chenliping0003@163.com (corresponding author)

Received: 5 September 2012
Accepted: 8 November 2012

Abstract

We have studied the electrically tunable strain effects on phase-separated Pr_0.5Sr_0.5MnO₃ films epitaxially grown on ferroelectric 0.67Pb(Mg_1/3Nb_2/3)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.