Microwave Dielectric Properties of Single-Crystal KTaO3 and SrTiO3 at Cryogenic Temperatures

Published

May 10, 2005

Author(s)

Richard G. Geyer, Jerzy Krupka, Billy F. Riddle, L. A. Boatner

Abstract

Microwave dielectric properties of single-crystal incipient ferroelectrics, KTaO₃ and SrTiO₃, have been measured at cryogenic temperatures. Cylindrical specimens were used as TEon1 mode and quasi-TE011 mode dielectric resonators at temperatures ranging from 4K to 300K. Conductive losses of the measurement resonant structures were taken into account, both as a function of frequency and temperature, so that uncertainties in the evaluated dielectric losses were plus or minus}0.5%. The evaluated real permittivities of KTaO3 and SrTiO3 exhibit no ferroelectric transition, and remain paraelectric down to 4 K, consistent with soft mode stabilization by zero-point quantum flucuations. Dielectric loss tangent values of KTaO3 at 3GHz were 4.2x10^-5 at 5.4 K, 8.9x10^-5 at 77 K, and 1.4x10^4^ at 300K, while those of srTiO₃ were 3.4x10^-3 at 5.4K, 2.4x10⁴ at 77K, and 3.8x10⁴ at 300 K. Results of the complex permittivity measurements are compared with theoretical predictions from a modified Devonshire phenomenological model.

Citation

Journal of Applied Physics

Issue

97

Pub Type

Journals

Keywords

dielectric properties, ferroelectrics

Citation

Geyer, R. , Krupka, J. , Riddle, B. and Boatner, L. (2005), Microwave Dielectric Properties of Single-Crystal KTaO₃ and SrTiO₃ at Cryogenic Temperatures, Journal of Applied Physics (Accessed October 14, 2024)