Influences of Al2O3/Nb2O5 co-doping on structural evolution and dielectric properties of Zn0.5Ti0.5-x(Al0.75Nb0.35)xNbO4 (0 ≤ x ≤ 0.3) ceramics. (February 2019)

• Record Type: Journal Article
• Authors: Yang, H Y; Zhang, S R; Yang, H C; Yuan, Y; Li, E Z
• Is Part Of: IOP conference series. Volume 479(2019)
• Publication Date: 2019-02
• Subjects: Materials science -- Periodicals; 620.1105
• DOI: 10.1088/1757-899X/479/1/012051
• Languages: English
• ISSNs: 1757-8981

Abstract

Abstract: In present study, the influences of Al2 O3 and Nb2 O5 co-doping for Ti site on structure and microwave dielectric performances of Zn0.5 Ti0.5- x (Al0.75 Nb0.35 ) x NbO4 ceramics were discussed. Pure ixiolite-structured Zn0.5 Ti0.5 NbO4 solid solution is prepared when x ≤ 0.15. Phase transformation takes place at 0.2 ≤ x ≤ 0.3, where columbite ZnNb2 O6 phase exists. The dielectric constant (ϵr ) of ceramics presents a decline trend, which is attributed to the decrease of dielectric polarizability (0 ≤ x ≤ 0.15) and the formation of ZnNb2 O6 phase (0.2 ≤ x ≤ 0.3). The quality factor (Q × f), however, decrease till x = 0.15 and increase after that. The temperature coefficient of resonant frequency (τf ) value varies consistently with the densification. Typical dielectric ceramics ( x = 0.3) was synthesized at 115°C: a ϵr of 25.79, a Q × f about 56114 GHz and a τf of -78.18 ppm/°C, were obtained.