No abstract

A copper hydroxynitrate of stoichiometry Cu 2 (OH) 3 NO 3 , analogous to the layered double hydroxide family, was synthesized by the so-called controlled double jet precipitation technique, and by hydrolysis of urea in the presence of copper nitrate. Special attention has been focused on the size, morphology and agglomeration tendency of the particles. The aim of this work is to define the optimum precipitation conditions in terms of quality and dispersability of the recovered product. Such platelet-like particles can be used as anisotropic fillers in nanocomposite materials. Several reaction parameters such as flow and concentration of the reactant solutions, design of the reactor and addition of a growth modifier were studied. r

LiMn 2-x Ti x O 4 compounds with 0 ≤ x ≤ 1 were prepared by solid state reaction and Pechini technique. Powder X-ray diffraction showed that all samples crystallize with the spinel crystal structure (S.G. Fd 3 m). The cubic unit-cell parameter increases with Ti content.The influence of the Ti content and cationic distribution on the magnetic properties of the compounds was studied by measuring the temperature and magnetic field dependences of the magnetization : substitution by non magnetic d 0 Ti 4+ ions appeared to weaken the magnetic interactions between manganese ions. The electrical properties of LiMnTiO 4 were studied by AC impedance spectroscopy and DC polarisation measurements, which revealed the electronic character of the conduction process.

No abstract

No abstract

No abstract

No abstract

No abstract