Microstructure, Magnetic, and Magnetoresistance Properties of La0.7Sr0.3MnO3:CuO Nanocomposite Thin Films

(La0.7Sr0.3MnO3)(0.67):(CuO)(0.33) (LSMO:CuO) nanocomposite thin films were deposited on SrTiO3 (001), LaAlO3 (001), and MgO (001) substrates by pulsed laser deposition, and their microstructure as well as magnetic and magnetoresistance properties were investigated. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that LSMO:CuO films grow as highly textured self-assembled vertically aligned nanocomposite (VAN), with a systematic domain structure and strain tuning effect based on the substrate type and laser deposition frequency. A record high low-field magnetoresistance (LFMR) value of similar to 80% has been achieved in LSMO:CuO grown on LaAlO3 (001) substrate under high frequency. Detailed analysis indicates that both the strain state and the phase boundary effect play a significant role in governing the overall LFMR behavior.