Superconducting properties of thin films of CeRu 2

Abstract

Thin films of CeRu2 have been prepared with sharp superconducting transitions at temperatures of about 5.6K at large thickness, slowly decreasing to 4K around 50 nm. Below 50 nm the superconducting transition temperature decreases abruptly. The flux pinning properties of the thicker films are very anomalous. At low fields the pinning force Fp is very high, of the order of 109N/m3, and probably due to the strong disorder, but Fp drops to zero at unusually low reduced fields. This leads to a field- temperature phase diagram with an upper critical field line quite similar to the one for bulk crystals, but with an irreversibility line which lies much lower; it cannot be described with conventional theories for either 2D or 3D vortex lattice melting.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.