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An exhaustive microstructural characterization is reported for the LiBH 4-MgH 2 reactive hydride composite (RHC) system with and without the Ti-isopropoxide additive. X-ray diffraction (XRD) with Rietveld analysis, transmission electron microscopy (TEM) coupled to energy dispersive X-ray analysis (EDX), selected area electron diffraction (SAED) and electron energy loss spectroscopy (EELS) are presented in this paper as the first time for this system in all sorption steps. New data are reported regarding average crystallite and grain size, microstrain, phase formation and morphology that contribute to the understanding of the reaction mechanism and the influence of the additives on the kinetics. Microstructural effects, related to the high dispersion of titanium based additives, results in a distinct grain refinement of MgB 2 and an increase of reaction sites which causes acceleration of desorption and absorption reactions. Considerations on stability of phases under e-beam irradiation have been also reported.

TiO 2 thin films in the form of anatase have been prepared by plasma enhanced chemical vapor deposition (PECVD) at 523 K as the substrate temperature and a low working pressure. The study of the microstructure and texture of the films at different stages of deposition show that their growth follows the Kolmogorov's model developed to describe the evolution of crystalline films from a saturated homogeneous medium. An additional characteristic feature of the growth process by PECVD is the formation of different crystalline domains, particularly at low deposition rates. The effects of this parameter and of the characteristics of the substrate on the growing process are also addressed.