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On a nonclassical thermoviscomechanical stress in the vortex field in the type‐II superconductor
Author(s) -
Maruszewski B. T.
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200572711
Subject(s) - vortex , condensed matter physics , pinning force , physics , type ii superconductor , magnetic flux , flux pinning , superconductivity , lorentz force , magnetic field , mechanics , high temperature superconductivity , quantum mechanics , critical current
Magnetic flux can penetrate a type‐II superconductor in the form of Abrikosov vortices (also called flux lines, flux tubes, or fluxons), each carrying a quantum of magnetic flux. These tiny vortices of supercurrent tend to arrange themselves in a triangular and/or quadratic flux‐line lattice, which is more or less perturbed by material inhomogeneities that pin the flux lines. Pinning is caused by imperfections of the crystal lattice, such as dislocations, point defects, grain boundaries, etc. Hence, a honeycomb‐like pattern of the vortex array presents some mechanical properties. If the Lorentz force of interactions between the vortices is much bigger than the pinning force, the vortex lattice behaves elastically. So we assume that the pinning force is negligible in the sequel and we deal with soft vortices. The vortex motion in the vortex lattice and/or creep of the vortices in the vortex fluid is accompanied by energy dissipation. Hence, except for the elastic properties, the vortex field is also of a viscous character. The main aim of the paper is a formulation of a thermoviscoelastic stress‐strain constitutive law consisted of coexistence of the ordered and disordered states of the vortex field. Its form describes an auxetic‐like thermomechanical (anomalous) property of the vortex field. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)