Single Source Precursor for PAD-LaMnO3 Thin Films

A new lanthanum and manganese ethylenediaminetetraacetate (EDTA) coordination polymer (EDTA(4-) = [(CH2N)(2)(CH2-COOH)(CH2COO)(4)]) was synthesized from La(NO3)(3) and Mn(NO3)(2) reagents, ethylenediaminetetraacetic acid, and water at room temperature. The structure of the new compound formed, [{La2Mn3(EDTA)(3)(H2O)(11)}center dot 12H(2)O](n), was determined by the single crystal X-ray diffraction technique. The synthesis and characterization of the La(III) and Mn(II) coordination complex, characterized by FTIR spectroscopy, thermogravimetry, and differential thermal analysis of the complex, are envisaged. X-ray crystal structure determination indicates that seven- and four-coordinate modes between La(III)/Mn(pi) and H(4)EDTA exist. [{La2Mn3(EDTA)(3)(H2O)(11)}center dot 12H(2)O](n) crystallizes in the monoclinic space group C2 with unit cell parameters of a = 16.1227(17) angstrom, b = 14.8049(16) angstrom, c = 14.8736(16) angstrom, and beta = 116.107(2)degrees. Using this precursor, LaMnO3 (LMO) epitaxial thin films were grown by the polymer-assisted deposition (PAD) method on (100)SrTiO3 (STO) single crystalline substrates at a temperature of 900 degrees C. The LMO crystallized films exhibit a (001)LMO/(001)STO out-of-plane epitaxial relationship and a smooth surface morphology.