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Relationship of Crystal Structure and Microwave Dielectric Properties in Ni 0.5 Ti 0.5 NbO 4 Ceramics with Ta Substitution
Author(s) -
Huang Xin,
Zhang Huaiwu,
Lai Yuanming,
Wang Gang,
Li Mingming,
Hong Caiyun,
Li Jie
Publication year - 2018
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201800016
Subject(s) - octahedron , dielectric , natural bond orbital , chemistry , analytical chemistry (journal) , crystal structure , ceramic , crystallography , doping , tantalum , mineralogy , inorganic chemistry , materials science , molecule , organic chemistry , optoelectronics
We have prepared Ni 0.5 Ti 0.5 Nb 1– x Ta x O 4 microwave dielectric ceramics using a traditional solid‐state reaction method. The influence of Ta 5+ substituted at the Nb 5+ site on the crystal structures and dielectric properties of Ni 0.5 Ti 0.5 Nb 1– x Ta x O 4 ceramics is discussed. Structural refinement indicates that the distortion in the oxygen octahedron is affected by Ta substitution. The dielectric constant is dependent on the polarization of the NbO 6 octahedron. The Q × f value is improved as the Ta content increases, because of the increasing packing fractions. The τ f value is mostly dominated by distortions of the Nb–O bonds ( δ Nb–O ); and δ Nb–O reduces with increasing Ta ion doping in the Nb site, which makes the τ f value decrease with increasing Ta content. Optimal microwave dielectric properties ( ε r = 48.5, Q × f = 17500 GHz, and τ f = 88.6 ppm °C –1 at the resonant frequency of 6.05 GHz) are obtained for Ni 0.5 Ti 0.5 Nb 1– x Ta x O 4 ceramics at x = 0.2.