Electron energy loss spectroscopy assessment of cationic migration in La2/3Ca1/3MnO3 thin films

Màster en Nanociència i Nanotecnologia curs 2006-2007. Directors: Francesca Peiró i Martínez and Jordi Arbiol i Cobos

In the present work Transmission Electron Microscopy (TEM) and Electron Energy Loss Spectroscopy (EELS) are applied for the evaluation of trivalent cationic migration in epitaxial thin films of La2/3Ca1/3MnO3 (LCMO). The first part of the work shows the comparative results of the growth by RF-sputtering of both annealed and as grown La2/3Ca1/3MnO3 (LCMO) layers of various thicknesses on (001) LaAlO3 (LAO) substrates. Lanthanum diffusion is detected for LCMO films grown on LAO as a function of annealing and layer thickness and is determined to play a major role in the degradation of the magnetic properties found in this system. In the second part, thin LCMO layers simultaneously grown, also by RF-sputtering, on (001) and (110) SrTiO3 (STO) are evaluated. La diffusion is also found in thin LCMO films grown on STO and the correlation with magnetic properties depending on the film thickness is discussed.