ANISOTROPIC COMPLEX PERMITTIVITY MEASUREMENTS OF MONO-CRYSTALLINE RUTILE BETWEEN 10 AND 300 K

The dielectric properties of a single crystal rutile (TiO2) resonator have been measured using whispering gallery modes. Q factors and reson ant frequencies were measured from 300 to 10 K. Q factors as high as 1 0(4), 10(5), and 10(7) were obtained at 300, 80, and 10 K, respectivel y. Using the whispering gallery mode technique we have determined accu rately the loss tangent and dielectric constant of monocrystalline rut ile and obtained much more sensitive measurements than previously repo rted. We show that rutile exhibits anisotropy in both the loss tangent and permittivity over the range from 10 to 300 K. (C) 1998 American I nstitute of Physics. [S0021-8979(98)03103-X].