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Study of the microwave dielectric properties of (La 1− x Sm x )NbO 4 ( x =0‐0.10) ceramics via bond valence and packing fraction
Author(s) -
Xiao Mi,
Gu Qingqing,
Zhou Ziqi,
Zhang Ping
Publication year - 2017
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.14930
Subject(s) - natural bond orbital , valence (chemistry) , dielectric , bond length , ceramic , materials science , analytical chemistry (journal) , temperature coefficient , crystallography , atomic packing factor , monoclinic crystal system , microstructure , chemical bond , mineralogy , chemistry , crystal structure , computational chemistry , density functional theory , composite material , organic chemistry , optoelectronics
The (La 1− x Sm x )NbO 4 ( x =0‐0.10) ceramics were prepared by the conventional solid‐state reaction method. The microstructure and the microwave dielectric properties were discussed in detail. The X‐ray diffraction patterns of (La 1− x Sm x )NbO 4 ( x =0‐0.10) showed that only a single monoclinic fergusonite structure of LaNbO 4 could be found. The dielectric constant (ε r ) was affected by the dielectric polarizabilities and the B‐site bond valence. The variation trend of Q × f 0 was in accordance with packing fraction. The temperature coefficient of resonant frequency (τ f ) had a close relationship with the B‐site bond valence, which was determined by the bond strength and bond length. When sintered at 1325°C for 4 hours, the (La 1− x Sm x )NbO 4 ceramics with x =0.08 exhibited enhanced microwave dielectric properties: ε r =19.37, Q × f 0 =62203 GHz and τ f =2.57 ppm/°C. In addition, we made an overview about the ceramics that possess the same packing fraction and bond valence relationships, the results show that this structure‐property relationship has a wide applicability.