CHARACTERISTICS OF FIRST-ORDER VORTEX LATTICE MELTING : JUMPS IN ENTROPY AND MAGNETIZATION

We derive expressions for the jumps in entropy and magnetization characterizing the first-order melting transition of a flux line lattice. In our analysis we account for the temperature dependence of the Landau parameters and make use of the proper shape of the melting line as determined by the relative importance of electromagnetic and Josephson interactions. The results agree well with experiments on anisotropic Y$_1$Ba$_2$Cu$_3$O$_{7-\delta}$ and layered Bi$_2$Sr$_2$Ca$_1$Cu$_2$O$_8$ materials and reaffirm the validity of the London model.