EMPIRICAL CORRELATION BETWEEN T-C AND THE TEMPERATURE-DEPENDENCE OF THE ELECTRONIC SPECIFIC-HEAT OF SUPERCONDUCTING LA2-XSRXCUO4 AT LOW-TEMPERATURES

We report precise measurements of the specific heat of seven samples o f superconducting La2-xSrxCuO4 (0.05 less than or equal to x less than or equal to 0.27) between 0.09 K and 1.5 K. When phonon and nuclear t erms are subtracted, the remaining, electronic, specific heat has the form alpha T-n, where n <1 for an samples and shows a smooth correlati on with T-c, having a minimum value in the optimally doped sample, x = 0.15. We discuss the possibility that this unconventional form of the electronic specific heat arises from localisation of the quasi-partic les at low temperatures.