ScienceAsia 22 (1996): 163-168 |doi: 10.2306/scienceasia1513-1874.1996.22.163

RATIO BETWEEN THE JUMP IN THE SPECIFIC HEAT AND THE THERMODYNAMIC CRITICAL FIELD FOR THE DOPED FULLERENE SUPERCONDUCTORS

I. M. TANG

ABSTRACT: The jump in the specific heat at T, and the critical fields of Type II superconductors are connected through a thermodynamic relation. The relationship leads to (C/T_c) = [dH₂(T_c)/dT]²/8²² where H_c2(T) is the upper critical field and is the ratio between the penetration depth and coherence length. Application of this equation to the critical field data for the doped fu/lerene superconductor K₃C₆₀ yields a value for C/T_c, of 380 mJ/mole/K² which is far above the measured value of 68 13 mJ/mole/K². We find that this discrepancy could be due to the electrons in the alkali doped fullerene superconductor being coupled to both a high intramolecular vibration mode and a low lying intermolecular vibration mode. The strong coupling Eliashberg formalism is used.