The anomaly of the specific heat of La2-xSrxCuO4+δ near Tc


  • In memory of Prof. D. Wohlleben, who died 13 Juy 1992


The specific heat of three polycristalline samples of La2-xSrxCuO4+δ (x = 0.15, 0.15, 0.16) near Tc was measured with a resolution better than 0.1%. The anomaly at Tc is analysed for fluctuations for the first time. It is well described by a superposition of a mean field step and a contribution due to gaussian fluctuations. By a fit of a Lawrence-Doniach type of model to the specific heat near Tc we estimate ΔCMF and the anisotropic coherence lengths ξ and ξ⊥ of the superconductor.