Extended thermodynamics, effective elastic coefficients and electromagnetoelastic waves in superconducting layer (original) (raw)

The paper deals with the analysis of an influence of the thermal field and its relaxation properties on the compressional and flexural magnetoelastic waves propagation in a vibrating superconducting layer. The investigations have been confined only to the vortex elastic field in the type-II superconductor. The description is based on the extended thermodynamical model of interactions. Contrary to the existing dynamical descriptions of electromagnetothermoelastic interactions in solids and/or in the magnetic vortex field of elastic character in the type-II superconductor, the influence of the thermal field on the electromagnetoelastic field (or electromagnetoelastic waves in such a medium) has been considered by the use of the effective elastic coefficients dependent on temperature and the relaxation time of the thermal field in low temperatures. Keywords Thermodynamics of superconductors • Magnetic vortex waves • Effective elasticity 1 Introduction Electromagnetothermoelastic (EMTE) coupled interactions occur in many physical systems. They are observed, among others, in solids of different electromagnetic properties such as dielectric, semiconducting and superconducting ones. Particularly, if they take place in low temperatures, the most interesting are materials of superconducting properties. The external magnetic field penetrates the type-II superconductor (SC2) in the form of the Abrikosov vortices (see [2-4]). Around each of them the supercurrent flows so there exist the Lorentz force interactions among them creating an additional mechanical (elastic) field (except for the mechanical one of the superconducting material as itself). Near the lower critical magnetic field intensity limit H c1 , that field has also viscous character. Since the superconductivity occurs in the low temperatures where the thermal field has the relaxation character, the most suitable thermodynamical model is the extended one [8-10] to describe more precisely dynamical interactions and processes in the EMTE field in the SC2 and its vortex field. Communicated by Attila Imre.