Effect of composite methods on the phase transition and microwave performances of ZnZrNb_1.99(Sn_0.5W_0.5)_0.01O₈–TiO₂ system

Abstract

Tri‐layer ZnZrNb1.99(Sn0.5W0.5)0.01O8–TiO2–ZnZrNb1.99(Sn0.5W0.5)0.01O8 and random distribution ZnZrNb1.99(Sn0.5W0.5)0.01O8@TiO2 ceramics with different mass fractions of TiO2 were initially synthesized. The effects of the laminated cofiring and the random distribution processes on the crystal structure and microwave dielectric properties of the composite ceramics were investigated. The advantages of the unique tri‐layer architecture were fully demonstrated. It not only allows the effects of the chemical reactions between ZnZrNb1.99(Sn0.5W0.5)0.01O8 and TiO2 can be effectively limited to a narrow region (∼20 μm in width) within the ZnZrNb1.99(Sn0.5W0.5)0.01O8/TiO2 interfaces, and acts as the “glues” to bond each layer well. The layers are well connected and the possibility of deterioration of Q× f values during the modification process can be greatly reduced. When compared with ZnZrNb1.99(Sn0.5W0.5)0.01O8@TiO2 ceramics with random distribution type, the tri‐layer design can produce a roughly 60% improvement in Q× f value with no noticeable loss in dielectric constant while maintaining temperature stability. After sintering at 1340°C for 6 h, ZnZrNb1.99(Sn0.5W0.5)0.01O8–TiO2–ZnZrNb1.99(Sn0.5W0.5)0.01O8 tri‐layer ceramics exhibited excellent dielectric properties (εr = 30.29, Q× f = 56,880 GHz, and τf = −5.73 ppm/°C) with 0.05 wt% TiO2, and the cooperative optimization of microwave dielectric properties was achieved. The current research provides a strategy for synthesizing microwave dielectric devices with high dielectric properties for applications in 5G network communications.