Electric-field control of electronic transport properties and enhanced magnetoresistance in La0.7Sr0.3MnO3/0.5BaZr(0.2)Ti(0.8)O(3)-0.5Ba(0.7)Ca(0.3)TiO(3) lead-free multiferroic structures

Abstract

We report the fabrication of lead-free multiferroic structures by depositing ferromagnetic La0.7Sr0.3MnO3 (LSMO) polycrystalline films on polished 0.5BaZr(0.2)Ti(0.8)O3-0.5Ba(0.7)Ca(0.3)TiO(3) (BZT-BCT) piezoelectric ceramic substrates. By applying electric fields to the BZT-BCT along the thickness direction, the resistivity of LSMO films can be effectively manipulated via the piezoelectric strain of the BZT-BCT. Moreover, the LSMO polycrystalline films exhibit almost temperature independent and significantly enhanced magnetoresistance (MR) below T-C. At T = 2K and H = 8 T, the MR of polycrystalline films is approximately two orders of magnitude higher than that of LSMO epitaxial films grown on (LaAlO3)(0.3)(SrAl1/2Ta1/2O3)(0.7) single-crystal substrates. The enhanced MR mainly results from the spin-polarized tunneling of charge carriers across grain boundaries. The LSMO/BZT-BCT structures with electric-field controllable modulation of resistivity and enhanced MR effect may have potential applications in low-energy consumption and environmentally friendly electronic devices. Published by AIP Publishing.