  Boron-doped diamond granular thin films are known to exhibit
superconductivity with an optimal critical temperature of Tc = 7.2K. Here we
report the measured complex surface impedance of Boron-doped diamond films in
the microwave frequency range using a resonant technique. Experimentally
measured inductance values are in good agreement with estimates obtained from
the normal state sheet resistance of the material. The magnetic penetration
depth temperature dependence is consistent with that of a fully-gapped s-wave
superconductor. Boron-doped diamond films should find application where high
kinetic inductance is needed, such as microwave kinetic inductance detectors
and quantum impedance devices.
