Nanocomposite films with magnetic field sensing properties

Abstract

La0.67Sr0.33MnO3 (LSMO) and LSMO:ZnO nanocomposite thin films were fabricated on SiO2/Si and (0001) Al2O3 substrates through solution deposition routes. The LSMO grain size reduced in the composite films as compared to that in pure LSMO film resulting in a larger volume fraction of grain boundaries. Further, compositional or magnetic disorder at the grain boundary region resulted in a reduction of the ferromagnetic-paramagnetic and metal–insulator transition temperatures in LSMO:ZnO films. The magnetoresistance (MR) behavior in the composite films was revealed to be dominated by extrinsic effects with large values of MR at low temperatures and low applied fields. A maximum low-field MR value of −23.9% was observed at 0.5T and 10K with the field applied parallel to the current for LSMO:ZnO film on Al2O3, with a maximum field sensitivity of 632%/T.