Title :
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
fDate :
28 May-1 June 2002
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 Ba6-3xR8+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 (εr) 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; Ba6-3xR8+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;
Conference_Titel :
Applications of Ferroelectrics, 2002. ISAF 2002. Proceedings of the 13th IEEE International Symposium on
Print_ISBN :
0-7803-7414-2
DOI :
10.1109/ISAF.2002.1195874
