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Phase evolution and microwave dielectric properties of novel LiAl 5− x Zn x O 8−0.5 x ‐based (0 ≤ x ≤ 0.5) ceramics
Author(s) -
Lan XueKai,
Li Jie,
Li JiaPu,
Wang Fei,
Lu WenZhong,
Wang XiaoChuan,
Lei Wen
Publication year - 2020
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/jace.16791
Subject(s) - analytical chemistry (journal) , dielectric , spinel , materials science , temperature coefficient , phase (matter) , ceramic , microwave , dielectric spectroscopy , doping , mineralogy , crystallography , chemistry , metallurgy , electrode , physics , optoelectronics , organic chemistry , quantum mechanics , chromatography , electrochemistry , composite material
Novel LiAl 5− x Zn x O 8−0.5 x microwave dielectric ceramics were synthesized through a solid‐state reaction route. Phase evolution of LiAl 5− x Zn x O 8−0.5 x was determined by XRD analysis. The XRD results indicated that the phase compositions had a P 4 3 32 space group when 0 ≤ x ≤ 0.2 and a spinel structure when 0.3 ≤ x ≤ 0.5. The dielectric constant ( ε r ) of this series’ solid solutions decreased with the increase in Zn doping content, which was in good agreement with the Clausius‐Mossotti relation. Oxygen vacancy and the decreased degree of order degraded the quality factor ( Q × f ) of the two structures. The deterioration in quality factor was further verified by impedance spectroscopy. The temperature coefficient of the resonant frequency ( τ f ) decreased with the increase in x and was correlated with the unit cell volume. Finally, CaTiO 3 was used as a compensation material to obtain a near‐zero τ f of the LiAl 5 O 8 ceramic.