Sb. Ota et al., GINZBURG-LANDAU THEORY OF SPECIFIC-HEAT ANOMALY OF HIGH-TC SUPERCONDUCTORS IN MAGNETIC-FIELD, Physica. B, Condensed matter, 194, 1994, pp. 1387-1388
The change in specific heat by the application of magnetic field (B(a)
approximately 1 T) in the case of the high-T(c) superconductors is ex
amined phenomenologically by the Ginzburg-Landau theory of anisotropic
type-II superconductors. The observed large reduction of specific hea
t anomaly just below the superconducting transition is explained quant
itatively. We have obtained the expression for the change in specific
heat in a magnetic field (DELTAC) for any general orientation of B(a)
with respect to the crystallographic c-axis. We also present the resul
t for a polycrystalline sample. DELTAC is shown to be linear in (B(a)/
T(c)[t/(1 - t)] for temperatures slightly below T(c), where t = T/T(c)
. The slope of this linear behaviour is found to be related to the ani
sotropy of the effective mass.