Effect of Co2+ Substitution on the Microwave Dielectric Properties of LiZnPO4 Ceramics

• DOI: 10.1007/s11664-018-6665-z
• Publication Date: 2018-10-02T11:35:12Z
• Authors: Rui Peng; Yuanxun Li; Guoliang Yu; Yongcheng Lu; Sheng Li
• Keywords: 0103 physical sciences; 01 natural sciences

The microstructure, sintering behavior, and microwave dielectric properties of LiZn1−xCoxPO4 (x = 0.00–0.10) ceramics were investigated. All these materials were synthesized by the traditional solid-state reaction method. Component and microstructure of the ceramics were verified by x-ray diffraction (XRD) patterns and scanning electron microscopy (SEM), respectively. The substitution of Co2+-ion to Zn2+-ion would improve the densification level of composite ceramics, and the microwave dielectric properties would be changed accordingly. An excellent microwave dielectric property of LiZn1−xCoxPO4 (x = 0.00–0.10) was achieved when x = 0.07 (ɛr = 5.43, Q × f = 35,446 GHz at 15 GHz, τf = − 77.4 ppm/°C). In order to achieve reliable thermal stability, Pb1.5Nb2O6.5 was used to adjust its τf value. The LiZn0.93Co0.07PO4 ceramics with 6 vol.% Pb1.5Nb2O6.5 sintered at 750°C for 4 h shows a near-zero τf value of − 4.4 ppm/°C, ɛr = 6.09, Q × f = 14,305 GHz (at 15 GHz), and there was no chemical reaction between Pb1.5Nb2O6.5 and LiZn0.93Co0.07PO4. The composite ceramics are promising materials for millimeter-wave device applications in the field of low temperature co-fired ceramics.