P. Palade

Polymer-derived microcellular SiOC foams with magnetic functionality

SiOC microcellular ceramic foams possessing soft-ferromagnetic properties were produced from a pre-ceramic polymer, poly-methyl-methacrylate microbeads (PMMA) (used as sacrificial pore formers) and iron silicide micro-powders (as functional filler). The interactions between the matrix and the filler were studied as a function of the amount of powders introduced and the pyrolysis temperature. Magnetic and mechanical properties were also investigated.

On the Passivation of the Metallic Surfaces from the Nuclear Plant Water Circuits

Samples obtained from the hot conditioning and hot performance procedures have been investigated by CEMS. Various types of substrates were considered. The surface phases were assigned to magnetite, α-Fe, wüstite and to spinel solid solutions. The data have been analyzed taking into account the compound stoichiometry, the number of iron unequivalent positions appeared in each identified phase and the relative ratio of the formed products.

The nature of the hydrogen bond in the LaNiSnH2 and NdNiSnH hydrides

The electronic structure of LaNiSn and NdNiSn compounds and their hydrides has been studied by first principles calculations and variable temperature 119Sn Mossbauer spectroscopy and the nature of the hydrogen-metal bond is discussed. The analysis of the electronic density of states (DOS) in both compounds before and after hydrogenation indicates an hybridization of the Sn, Ni, and H orbitals. The partial Sn-p DOS of LaNiSnH2 gives evidence for a lower symmetry of electron density around tin atoms compared to LaNiSn, according to the larger quadrupole splitting in the corresponding Mossbauer spectrum. Theoretical and experimental Mossbauer parameters agree very well for all samples.