A first-principles study and some applied researches of high-temperature superconductors and other low-dimensional functional materials

Resumo

This thesis is divided in two parts: Part I presents novel results using a first-principle study of the high-temperature cuprate superconductor (HTS) materials, performed in the framework of a collaboration with Professor A.J. Leggett, in whose laboratory I performed different stays. The study presents an extension, to the case of HTS, of equations originally derived for simple superconductors by G.V. Chester. They link the energy saved by the superconductivity with the structural properties of the materials. Then, we apply these extended equations to various prototypical HTS. Part II is devoted to various applied studies in different micro and nanostructured functional materials and devices. We divided these studies in two groups: In part IIA, we focus again on HTS and propose structuration designs that optimize their functionality as bolometric sensors of electromagnetic radiation (a development that led to our Spain’s patent application coded P201930020) and we also study other structured HTS systems (2D dot-pattern structured films; hybrid superconductor+piezoelectric films). In part IIB, we study instead electrostatic nanostructured micropore (ENM) media of the type recently introduced by industry in various forms (among other, nanoalumina-coated microporous membranes) for filtration of nanofluids (liquids carrying nanoentities in suspension). By employing model equations previously developed in Santiago de Compostela, we find microgeometry configurations able to optimize the energy efficiency and performance of filters based on such media.