Elastic Constants of the Fluxoid Lattice Near the Upper Critical Field

Abstract

Abstract The elastic constants of the fluxoid lattice are calculated in terms of the reversible magnetisation curve by taking the appropriate derivatives of the free energy of the fluxoid assembly. The expressions obtained in previous work for the compressional modulus and for the shear modulus c 44 in magnetic fields well below H c2 are confirmed and their validity over the entire range of field between H c1 and H c2 is established. A new expression is derived for the shear modulus c 66 in high fields. It turns out that c 66 goes quadratically to zero if the applied field approaches H c2 .