Structure and electrical properties of (0.99-x)K_(0.5)Na_(0.5)Nb_(0.96)Sb_(0.04)O_3-0.01 BaZrO_3-xBi_(0.5)Na_(0.5)ZrO_3 lead-free piezoelectric ceramics

摘要

(1 − x)Zn~(0.9)Mg~(0.1)TiO~(3)–xZn~(0.15)Nb~(0.3)Ti~(0.55)O~(2)((1 − x)ZMT–xZNT) (x = 0.100, 0.125, 0.150, 0.175, 0.200) ceramics were prepared at 900 °C by conventional mixed-oxide method. The phase content, microstructure and microwave dielectric properties had been investigated in detail. Rietveld refinement shows the coexistence of Zn~(0.9)Mg~(0.1)TiO~(3), Zn~(0.15)Nb~(0.3)Ti~(0.55)O~(2), Zn(BO~(2))~(2)and Zn~(2)TiO~(4)phases. With ZnO–B~(2)O~(3)–SiO~(2)(ZBS) glass added, the ceramics can be sintered well at 900 °C with a smaller grain size of 0.12 µm and a higher relative density (> 95%). The microwave dielectric properties are largely influenced by the phase composition according to mixture rule. A typical sample of 0.825ZMT–0.175ZNT ceramic with optimal dielectric properties ( ε ~( r ) = 26.14, Q  ×  ƒ  = 27184 GHz, τ ~( ƒ ) = − 3.46 ppm °C_(−1)) was sintered at 900 °C for 4 h.