Carlos González Oliver

magnetic properties of glasses with high iron oxide content

A study of the magnetic properties of glasses with high iron oxide content has been carried out. This glass series was obtained by recycling goethite (FeOOH) industrial waste, with dolomite and glass cullet as complementary raw materials. The magnetisation as a function of applied magnetic field for these glasses was measured. According to the magnetic behaviour, which closely correlates with the iron content, these glasses can be classified as ferrimagnetic, superparamagnetic and paramagnetic. The magnetisation curves were analysed in terms of current models for these types of magnetic behaviour.

BaCuO2 - Ag interaction: a central feature in the densification of Ag - Y1Ba2Cu3O7-δ composites

Abstract Dilatometric and DTA / TGA measurements (in O 2 atmosphere) on Ag-123 composites indicate that silver affects dramatically the two principal reactions that provoke the unstabilization of Y 1 Ba 2 Cu 3 O 7-δ . These are the precipitation of 011 phase plus Yttrium rich liquid (900–930°C), and the peritectic reaction triggered by 011 fusion (980–1040°C). Silver increases, upon initial heating, the partial decomposition of 123 phase (ER). For pre-peritectic temperatures higher than the AgAgO eutectic temperature, it interacts with 011 phase for developing a “re-assembling mechanism”. A modified 123 phase named 123 ∗ is formed, containing doping levels of Ag, possibly as a layer of 123 ∗ around 123 grains. SEM / EDAX analysis show the superficial nature of the re-assembling phenomena.