Microstructural features of La2/3Ca1/3MnO3 layers of various thicknesses grown on top of (001) LaAlO3 substrates were studied by using transmission electron microscopy and electron energy loss spectroscopy. Films were of high microstructural quality but exhibited some structural relaxation and mosaicity both when increasing thickness or after annealing processes. The existence of a cationic segregation process of La atoms toward free surface was detected, as well as a Mn oxidation state variation through layer thickness. La diffusion would lead to a Mn valence change and, in turn, to reduced magnetization.

Cationic Diffusion in La2/3Ca1/3MnO3 Thin Films Grown on LaAlO3 (001) Substrates. S.Estradé, J.Arbiol, F.Peiró, L.Abad, V.Laukhin, L.Balcells, B.Martínez: Applied Physics Letters, 2007, 91[25], 252503