LaBaMnO films produced by dip-coating on a quartz substrate

The electrical transport and magnetoresistance properties of the polycrystalline La0.67Ba0.33MnO3 film produced on a quartz substrate were investigated first time. X-ray powder diffraction indicated that film sample has perovskite structure. Scanning electron microscope indicated that La0.67Ba0.33MnO3 film thickness is approximately 20 mu m and the average grain size of this sample varies between 8 and 10 mu m. La0.67Ba0.33MnO3 film showed a phase transition from paramagnetic to ferromagnetic at (Tc) 130 K and a metal-insulator transition at (T-MI) 137 K at 2 mT magnetic field. The upturn of the resistance observed at low temperatures (<49 K) was attributed to the Coulomb blockade and the strong structural disorder due to the large lattice mismatch and strain relaxation. A large magnetoresistance ratio (MR(%)) of 230% was observed at 125 K and 6 T magnetic fields. (C) 2007 Elsevier B.V. All rights reserved.