David M. Bastidas

Influence of the Sr content on the synthesis of Hg0.8Re0.2Ba2-xSrxCa2Cu3O8+δ at normal pressures

High-purity ceramics of the superconducting phases Hg0.8Re0.2Ba2-xSrxCa2Cu3O8+δ with 0≤x≤0.4 have been prepared by the vacuum sealed quartz tube technique using HgO as the internal source. The superconductors were prepared from stoichiometric precursor powders of elemental oxides and carbonates. The synthesis was carried out in two steps: first, a multiphase precursor with the nominal composition: Re0.2Ba2-xSrxCa2Cu3O8+δ was prepared in an oxygen atmosphere. Then, the precursor powder was mixed and pressed with stoichiometric additions of HgO and was encapsulated in an evacuated quartz tube. The pellets were annealed at different rates and temperatures in order to optimize the purity of the phase. Different Sr compositions were studied but single-phase materials were only obtained below x = 0.3 under the present normal pressure synthesis conditions.

Comportamiento mecánico y frente a corrosión de mortero y hormigón armado fabricado con escorias de incineradora de residuos sólidos urbanos

The authors are grateful to Projects BIA2011–27182 and BIA2012–32320 of the MINECO, Spain, for financial support. D.M. Bastidas gratefully acknowledges funding from the Ramon & Cajal Program of the Spanish Ministry of Economy, Industry and Competitiveness.