Magnetic and structural studies of LaMnO3 thin films prepared by atomic layer deposition

Here we report the results of structural, microstructural and magnetic property characterizations of both thin films and bulk samples of LaMnO3 (LMO). Thin films were deposited by the atomic layer deposition technique on silicon (1 0 0) substrates, whereas bulk samples were prepared by a citrate combustion route. Effects of varying thickness, annealing atmosphere and temperature were studied on both LMO sample classes. Single-phase perovskite crystal structure was confirmed by x-ray diffraction and Raman spectroscopy, in thin films annealed at 700 and 800 °C as well as in bulk samples. Thin films annealed in N2 or O2 atmosphere do not vary in the crystal structure, but differ by the oxygen stoichiometry, microstructure and magnetic properties. The Curie temperature in all LMO thin films annealed in N2 was found to be around 200 K, while it was around 250 K for the films annealed in O2 as well as for the bulk samples. (paper)