Microwave surface resistance of a superconducting Mo-Re alloy

By using a Mo0.75Re0.25alloy endplate on a Nb microwave cavity (TE011mode, resonant at 11.2 GHZ), an upper bound for the residual surface resistance of this alloy was shown to be 2.8 µ-ohm, a lower bound for the breakdown field was shown to be 102 G. In view of the fact that these properties were determined at 11.2 GHZ on the first Mo-Re endplate made with no particular effort devoted to optimization of surface quality, this material is deserving of further consideration for practical microwave applications.