Efeito da pressão em supercondutores de Hg-12(n-1)n e efeito Casimir na escala nanométrica.

Abstract

In this work will be presented a description in wich Tc has a pressure-dependent behaviour in Hg-12(n-1)n superconductors, that takes into account the Casimir effect by considering the CuO2 conducting layers to act as plasma sheets. The Casimir energy arises from the parallel plasma sheets (Cu–O planes) whenever these are separated by distances on nanometer scale. The Tc pressure dependence in Hg12(n-1)n superconductors can be described by a pressure-induced charge transfer together with intrinsic terms that are associated with the Casimir energy. For Hg12(n-1)n samples with optimum oxygen content, the charge transfer term vanishes, leaving an explicit expression for the intrinsic term. By picking up realistic parameters and inserting them in the expression for the Tc pressure dependence, we have a good agreement with experimental intrinsic term data observed in the mercury family Hg-12(n-1)n superconductors.