Magnetic and transport properties of chemical solution deposited (100)-textured La_0.7Sr_0.3MnO₃and La_0.7Ca_0.3MnO₃nanocrystalline thin films

Abstract

A study of the magnetic and electrical properties of (100)-oriented La0.7(Sr,Ca)0.3MnO3 thin films prepared by an optimized chemical solution deposition process on a (100) SrTiO3 single-crystal substrate is reported in this paper. The films were studied by high-resolution scanning electron microscopy, x-ray diffraction, vibrating sample magnetometer, ferromagnetic resonance and four-point-probe electrical measurements. A characteristic nanocrystalline texture with ∼15 nm crystallites is observed in both films. Remarkably, the resistivities of these films are three orders of magnitude smaller compared with unoptimized films grown even on the same substrate. The magnetotransport properties were determined as a function of temperature and applied field magnitude, and compared with bulk crystals and vacuum-deposited single crystalline (epitaxial) thin films as well as manganite nanostructures reported in the literature. Both films display large values of colossal magnetoresistance at around room temperature. Significantly, the magnetoresistance in (100) La0.7Sr0.3MnO3 thin film is observed to be highly linear even at low fields near the metal–insulator transition temperature. However, the dependence of these promising properties on the nanocrystal size remains to be explored.

Transport properties and microstructure of La0.7Sr0.3MnO3 nanocrystalline thin films grown by polymer-assisted chemical solution deposition

“…Among these methods, the CSD method has some advantages for the films deposition and growth such as low cost, high stability, and simple process. As for the CSD technique for the preparation of LSMO films, many researches about epitaxy, concentration of precursor solution, annealing, LFMR as well as the GBs on substrates of MgO, LaAlO 3 , Si, SrTiO 3 , and GaAs have been reported [18,19].…”