The fabrication and characterization of polycrystalline CuSn bolometers.

Polycrystalline CuSn thin films can be used as highly reproducible and easily fabricated bolometers for the temperature region of 1.3–3 K, an important range for both phonon pulse experiments and photon and particle detection. We report their fabrication and the dependence of their characteristic parameters on the evaporation melt and deposition conditions. The superconducting transition temperature of the films was determined predominantly by the alloy composition, the normal state resistance by the film thickness, and the bolometer sensitivity by the deposition rate. X-ray diffraction showed that the films were composites of Cu6Sn5 complexes and pure tin regions