Structure, infrared spectrum, and microwave dielectric properties of NiO–TiO2–Nb2O5 ceramics

• Published in: Solid state communications 2023-08, Vol.368, p.115183, Article 115183
• Main Authors: Yang, Hongyu, Chai, Liang, Xu, Chengzhi, Hu, Zhichao, Li, Zhimin, Xing, Mengjiang, Li, Enzhu
• Format: Article
• Language: English
• Subjects: A. Ceramics; C. Crystal structure; C. Spectroscopy; D. Microwave dielectric properties
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2023.115183

This study reports the crystal structure and intrinsic dielectric properties of NiO–TiO2–Nb2O5 ceramics. The NiO–TiO2–Nb2O5 system is crystallized as a rutile structure based on X-ray diffraction, Rietveld refinement, and TEM analysis. The sintering temperature has a certain positive effect on the dielectric constant and Q × f value, which is attributed to the reduction of porosity and the growth of crystals. Because of the particularity of the rutile structure, ionic polarizability cannot be used to evaluate the micro-polarization mechanism. Thus, using the far-infrared reflectance spectrum and complex dielectric function analysis, the high-frequency micro-polarization mechanism of the structure has been fully explained, which is expected to be applied to other high-εr dielectric ceramic systems. •High-εr NiO–TiO2–Nb2O5 dielectric material with a rutile structure was prepared.•Dielectric properties at microwave range were investigated.•Micro-polarization mechanism was identified by far-infrared reflectance spectroscopy.