摘要 : Two-dimensional films comprising of Bi clusters ranging in size from 25 to 100 Angstrom show an influence of the underlying matrix on normal state resistivity and the superconducting transition temperature T-c. This is in contrast... 展开 Two-dimensional films comprising of Bi clusters ranging in size from 25 to 100 Angstrom show an influence of the underlying matrix on normal state resistivity and the superconducting transition temperature T-c. This is in contrast to crystalline Bi. Quantum size effects are observed by changing the deposition temperature, which determines the cluster size. These observations can be attributed to superconductivity at the surface. Implications for the requirement of a critical number of superconducting clusters before the establishment of global phase coherence are briefly discussed. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 14] 收起