Nonlinear microwave properties of Nb(sub.3)Sn sputtered superconducting films

Microwave measurements of surface rf and dc field dependence on impedance of Nb(sub.3)Sn superconducting films deposited by planar magnetron sputtering on sapphire substrates are reported. Effects of a dc applied field with different orientations are consistent with the Coffey-Clem model. Field dependence at various temperatures and frequencies can be described consistently using a simple circuit modeling presence of weak superconducting regions in the sample. The studied material is potentially useful for accelerating cavities and passive microwave device applications.