Permittivity and microwave absorption of semi-insulating InP at microwave frequencies

Permittivity and dielectric losses of a Fe-doped semi-insulating bulk InP sample were determined at microwave frequencies from 4 to 300 K employing the whispering gallery mode technique. The dielectric loss tangent of the sample at 11 GHz exhibited a local maximum near 12 K. Since the dc conductivity at this temperature was not measurable in our sample the low temperature loss peak is attributed to the local displacement of bound charge carriers.