Microwave dielectric properties correlated to crystal structure: an analysis

Author

Ohsato, H. ; Kan, A. ; Kakimoto, K. ; Ogawa, H. ; Nishigaki, S.

Author_Institution

Dept. of Mater. Sci. & Eng., Nagoya Inst. of Technol., Japan

fYear

2002

fDate

28 May-1 June 2002

Firstpage

75

Lastpage

78

Abstract

Microwave dielectric properties, quality factor, dielectric constant and temperature coefficient of resonant frequency, are discussed based on the crystal structure analysis of two systems. The tungstenbronze-type like Ba_6-3xR_8+2xTi₁₈O₅₄ (R = rare earth) solid solutions and Y₂BaCuO₅ green phase are addressed as examples. The quality factor (Q·f) is improved by ordering due to phase transformation, compositional ordering of cations and purifying the composition. Dielectric constant (ε_r) is affected by volume of cation polyhedron, tilting of TiO₆ octahedron and polarizability of cations. Temperature coefficients of resonant frequency is studied by crystal structural analysis with different temperature.

Keywords

Q-factor; barium compounds; crystal microstructure; crystal structure; dielectric losses; dielectric materials; dielectric polarisation; microwave materials; permittivity; rare earth compounds; solid-state phase transformations; yttrium compounds; Ba_6-3xR_8+2xTi₁₈O₅₄; TiO₆ octahedron tilting; Y₂BaCuO₅; Y₂BaCuO₅ green phase; cation polarizability; cation polyhedron volume; cations compositional ordering; crystal structure; dielectric constant; microwave dielectric properties; phase transformation; quality factor; temperature coefficient of resonant frequency; Crystalline materials; Dielectric constant; Dielectric materials; Materials science and technology; Microwave technology; Mobile handsets; Q factor; Resonant frequency; Solids; Temperature;

fLanguage

English

Publisher

ieee

Conference_Titel

Applications of Ferroelectrics, 2002. ISAF 2002. Proceedings of the 13th IEEE International Symposium on

ISSN

1099-4734

Print_ISBN

0-7803-7414-2

Type

conf

DOI

10.1109/ISAF.2002.1195874

Filename

1195874