Specific Heat of Superconducting Fine Particles of Tin. I. Fluctuations in Zero Magnetic Field

Abstract

The electronic specific heat of fine particles of Sn with the average radius ranging 130–1100 Å has been measured over a temperature range of 0.4T_c–1.5T_c. As the particle size decreases, the peak of the specific heat due to the superconducting transition shifts towards lower temperature and becomes broader. This behavior is interpreted as the fluctuations in “zero-dimensional” superconductors. The temperature width of the critical region teaches 0.1T_c for the smallest particles. A method of normalization of the specific heat is proposed to describe the fluctuation specific heat around T_c. By use of this method, the experimental data for different particle sizes can be normalized to a unified form.