XRD and XPS characterization of mixed valence Mn3O4 hausmannite thin films prepared by chemical spray pyrolysis technique

Abstract

Spray pyrolysis technique has been employed successfully for the synthesis of single phase mixed valence spinel hausmannite (Mn3O4) thin films using alcoholic start solution of manganese acetate (Mn(CH3COO)(2)center dot 4H(2)O) on pyrex glass substrates at atmospheric pressure using air as a carrier gas. Thermal decomposition of the precursor in the temperature range 320-490 degrees C led to the formation of Mn3O4 phase as revealed from the thermogravimetry analysis. Prepared samples are characterized by Xray diffraction that shows spinel structure with space group I4(1)/amd. Pure and well crystallized specimen is subjected to X-ray photoelectron spectroscopy for the surface chemistry investigation of these systems at a molecular level. Surface Mn/O ratio is compared to the bulk composition of the sample. Atomic force micrographs revealed that the morphology and the surface grains of the films largely influenced by the substrate temperature. (C) 2009 Elsevier B. V. All rights reserved.