Bond characteristics and microwave dielectric properties of high‐Q materials in li‐doped Zn <sub>3</sub> B <sub>2</sub> O <sub>6</sub> systems
Qin Zhang, Xiaoli Tang, Maofeng Zhong, Yuanxun Li, Yulan Jing, Hua Su
Abstract
Abstract The bond characteristics, Raman spectroscopy, and microwave dielectric properties of Zn 3‐x Li 2x (BO 3 ) 2 ceramics prepared by solid‐state reaction method were investigated. According to the complex chemical bond theory, the bond ionicity and lattice energy of the B–O bond were proved to contributed more to the electric polarization and phase structure stability than that of A‐site bond. Thus, the B–O bond had a dominant effect on the dielectric constant and Q × f values. The optimization of the τ f value can be attributed to the bond valence. Moreover, the shift and full width at half maximum of the Raman peak were closely related to the dielectric constant and Q × f values, respectively. On the whole, Li + substitution contributed greatly to improve the temperature stability and reducing the dielectric loss of Zn 3‐x Li 2x (BO 3 ) 2 ceramics. Additionally, Zn 2.99 Li 0.02 (BO 3 ) 2 ceramics sintered at 850 °C exhibited satisfactory microwave dielectric properties of ε r =6.59, Q × f=122,030 GHz, τ f =−76.9 ppm/°C, and had good chemical compatibility with silver.