Uniaxial strain-modulated conductivity in manganite superlattice (LaMnO3/SrMnO3)

We have investigated the magnetic ordering and electrical conductivity transitions of (LaMnO3)(2)/(SrMnO3)(2) superlattices grown on SrTiO3 substrate based on density-functional theory. It is found that the uniaxial tensile strain along the z axis of about 1.4% induced a magnetic transition from antiferromagnetic to ferromagnetic ordering. At the interface the orbital order changes from a combination of x(2)-y(2) and 3z(2)-r(2) to x(2)-y(2) as strain becomes more compressive; as a result the electrical transport is transformed from three-dimensions to two-dimensions at the high uniaxial compressive strain. Our results suggest that the out-of-plane electrical conductivity can be modulated and controlled by uniaxial strain. (C) 2011 American Institute of Physics. [doi:10.1063/1.3548675]