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Measurements of the oxygen diffusivity of ceramic samples of the mixed ionic electronic conductor La0.6Sr0.4Co0.2Fe0.8O3−δ(LSCF6428) have shown the appearance of grain boundary tails in diffusion profiles at temperatures below 600 °C. Analysis of the tails yields values of the grain boundary diffusion products (Dgbδ). The activation enthalpies for the grain boundary and lattice diffusion are very close at 1.69 eV and 1.61 eV respectively, suggesting a common diffusion mechanism. Comparison with literature values on both lattice and grain boundary diffusion products have shown that values of Dgbδobtained for LSCF6428 are the highest yet recorded for any oxide material. The reasons for this high value are discussed, including the degree of nonstoichiometry of the parent lattice and the possible involvement of the twin boundaries found in these ceramic samples.

One of the most promising technologies in high efficiency solar cells is based on quaternary structures grown by epitaxial techniques as Metal Organic Chemical Vapour deposition (MOCVD). The semiconductors III-V structures are elaborated under tailored parameters, allowing the use of a broader area of the solar spectrum. Analytical techniques capable of providing accurate and precise information in cross sections about the composition and thickness of the layers are demanded. Secondary Ion Mass Spectrometry (SIMS) has been used for characterization of these structures due to its high depth resolution and sensitivity, stability and reproducibility. It was detected the diffusion process of Al and In across the cell interfaces and the layer diffusion over GaAs substrates. The Al diffusion was associated at incorrect incorporation of elements during growth process and the layer diffusion was associated at changes of manufacturing parameters. Such studies show the SIMS ability to diagnose of faults during the growth process, detection of impurities and incorrect diffusion of dopants that may affect the layer properties and the structure functionality.