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Abstract: Bilayered CoFe2O4/0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 nanocomposite films are successfully prepared on Pt/Ti/SiO2/Si substrate via simple sol–gel process. X-ray diffraction result reveals that there exists no chemical reaction or phase diffusion between the CoFe2O4 and 0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 phases. The microstructure is characterized by scanning/transmission electron microscopy (STEM). The composite thin films exhibit both strong ferroelectric and ferromagnetic responses at room temperature. The maximal magnetoelectric coupling coefficient of the nanocomposite films reaches up to 25mV/cmOe, occurs at a lower bias magnetic field (H dc) of 550Oe. [Copyright &y& Elsevier]

Abstract: The influence of additives on the reaction kinetics and microstructure refinement in LiBH4–MgH2 composites is investigated in detail. Indications of the rate-limiting processes during the reactions are obtained by comparison of the measured reaction kinetics with simulations with one specific rate-limiting process. The kinetics of the sorption reactions are derived from volumetric measurements as well as from in situ X-ray diffraction measurements. During desorption, the hydrogen is released at a constant rate, which is possibly correlated with the one-dimensional growth of MgB2 platelets. In contrast, the kinetic curves of the absorption reactions exhibit the typical shape of contracting-volume controlled kinetics. The microscopical interpretation of kinetic measurements are supported by transmission electron microscopy images confirming the formation of additive-nanostructures in the grain boundaries upon cycling. The present investigations underline the importance of the additives as nucleation substrates and the influence of microstructure on the reaction kinetics. [Copyright &y& Elsevier]