Cation and oxygen nonstoichiometry in R-Mn-O (R = La, Nd) bulk samples andthin films

Using injection MOCVD technique a series of epitaxial thin films of La and Nd manganites were prepared. Epitaxial stabilisation of high-pressure phase NdMn7O12 in thin films was observed for low Nd content. For ceramic sample s reduced in the flowing Ar with increase of La-vacancy concentration Mn2appearance and collapse of static JT-distortion were observed. Oxidation of manganites stabilises vacancies in A-sublattice of perovskite, which resul ts in the broadening of homogeneity area. For La/Mn and Nd/Mn cation-stoich iometric composition 1 : 1 a shift of oxygen solubility boundary was observ ed. (C) 2000 Elsevier Science B.V. All rights reserved.