Colossal electroresistance in La0.8Ca0.2MnO3 films on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrates
Department of Physics, the University of Hong Kong - Pokfulam Road, Hong Kong
2 College of Physics and Electronic Information Science, Tianjin Normal University - Tianjin 300074, China
Accepted: 7 February 2012
Epitaxial La0.8Ca0.2MnO3 (LCMO) thin films with varied thicknesses were successfully grown on 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) substrates with pulsed-laser deposition. Due to a large lattice mismatch between LCMO and PMN-PT, in-plane tensile strain was introduced into the LCMO layers. The tensile strain could be controlled by varying the layer thickness of LCMO. It was found that the in-plane tensile strain in LCMO layers could enhance the electroresistance (ER) effect significantly. A maximum value of ER ((R10 μA−R1 mA)/R10 μA×100%) was found to be ∼80% in a 10 nm thick LCMO film that suffered a 2.21% in-plane tensile strain. The mechanism for the impact of strain on the ER effect is discussed within the framework of the electron-lattice coupling and the phase separation scenario.
PACS: 73.50.-h – Electronic transport phenomena in thin films / 77.65.-j – Piezoelectricity and electromechanical effects / 75.70.-i – Magnetic properties of thin films, surfaces, and interfaces
© EPLA, 2012