Microwave properties of a rutile resonator between 2 and 10 K

Abstract

We report new microwave measurements of the anisotropic loss tangent and permittivity of rutile using well confined `whispering gallery' type modes of a shielded dielectric resonator. We report the first measurement of the two independent components of the loss tangent tensor, as well as the lowest measurement yet of the total loss tangent of parallel to the crystal c-axis and perpendicular to the c-axis, both measured at 3 K. We show that the mode frequency dependence possesses two stationary points in the temperature range 2-10 K and explain this dependence in terms of the competing effects of incidental paramagnetic impurities in the rutile, the variation of the rutile's permittivity with temperature and the thermal expansion of the material. We give the first measurements of the anisotropic permittivity of rutile at low temperatures.

Nonlinear and Quantum Optics with Whispering Gallery Resonators

“…Another application of the high-Q structures is related to the study of weak attenuation of microwaves in nominally transparent materials [34,42,46,47] and the material permitivity [48,49]. A variety of nonlinear microwave phenomena can also be observed in WGM resonators [50].…”

Microwave properties of MgB/sub 2/ thin films

“…Indeed, MgB seems to comprise values of the order or less than this error margin, because (4.2 K) for a MgB was found almost to be the same as with niobium film. In order to improve the measurement resolution a rutile puck has been used to measure because of its higher dielectric constant [27], [28]. In this case the field energy concentration inside the puck works more effectively and the maximum with a niobium reference sample is about a factor of ten higher.…”

Dielectric and conductor-loss characterization and measurements on electronic packaging materials

“…A circle fit procedure yields a more accurate quality factor and is summarized in [109]. (62) The relative permittivity is obtained from the resonant frequencies of a cavity. The attenuation constant in a microstrip has been calculated [132].…”