Temperature and magnetic field dependence of the induced magnetization in macroscopic samples due to the proximity effect

We have applied the Ginzburg-Landau equations to calculate the behavior of the diamagnetism of macroscopic samples consisting of a normal metal in contact with a superconductor. In particular, the calculation focuses on the temperature region above the superconductive transition temperature (Formula presented) of the normal metal. We have compared these calculations with experimental measurements of the temperature (0.006-1 K) and magnetic field (Formula presented) dependence of the diamgnetism for several samples of Be (Formula presented) and W (Formula presented) in contact with the superconductor Al (Formula presented) The agreement between the predictions and measurements is quite good and confirms the approach of using the Ginzburg-Landau model to calculate the proximity effect in macroscopic normal systems above their superconductive transitions. © 1997 The American Physical Society.

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