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Contribution of Structure to Temperature Dependence of Resonant Frequency in the (1 − x )La(Zn 1/2 Ti 1/2 )O 3 · x ATiO 3 (A = Ca, Sr) System
Author(s) -
Cho SeoYong,
Youn HyukJoon,
Lee HyoJong,
Hong Kug Sun
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00737.x
Subject(s) - permittivity , octahedron , crystal structure , x ray crystallography , materials science , dielectric , temperature coefficient , analytical chemistry (journal) , crystallography , diffraction , chemistry , physics , optics , optoelectronics , chromatography , composite material
The crystal structure and microwave dielectric properties of the (1 − x ) La(Zn 1/2 Ti 1/2 )O 3 · x SrTiO 3 and (1 − x )La(Zn 1/2 Ti 1/2 )O 3 · x CaTiO 3 system were investigated. X‐ray powder diffraction showed that cation ordering disappeared at x > 0.3 for both systems. However, infrared spectra demonstrated that short‐range cation ordering could exist at x = 0.4. Permittivity and the temperature coefficient of the resonant frequency (τ f ) of both systems exhibited nonmonotonic variations with composition. Both systems exhibited a τ f of zero at the same composition of x = 0.5 although the τ f of SrTiO 3 was about two times larger than that of CaTiO 3 . The behavior of the permittivity and τ f were described by the tilting of oxygen octahedra and cation ordering. The relation between τ f and cation ordering of La(Zn 1/2 Ti 1/2 )O 3 was discussed in conjunction with the experimental results on metal halides. It is suggested that cation ordering induced a negative τ f and suppressed the increase of permittivity for compositions between x = 0 to x = 0.5 for (1 − x )La(Zn 1/2 Ti 1/2 )O 3 · x SrTiO 3 and (1 − x )La(Zn 1/2 Ti 1/2 )O 3 · x CaTiO 3 systems.