Abstract
The influence of thermal diffusion and temperature nonuniform distribution on ac loss of high-temperature superconductors has been investigated. Asymptotic solutions of magnetic and electric fields and ac loss are presented in the form of power series of λh, the normalized frequency of the external ac magnetic field. It reveals that influences of thermal diffusion on the ac loss behavior of high-Tc superconductors include: (i) a weak frequency dependence of ac loss per cycle, i.e., ac loss per cycle increases with frequency in the incomplete field penetration, but decreases with frequency in the complete field penetration; (ii) nonuniform temperature distribution in the sample with the highest temperature located in the center; and (iii) existence of a critical frequency at which the superconductivity is destroyed at the hottest point in the sample.