Phase transformation and dielectric properties of Bi2((Zn1/3Nb2/3)1-xTix)2O7 ceramics

Abstract

ABSTRACTBi2((Zn1/3Nb2/3)1-xTix)2O7 weberite ceramics with 0.3≤x≤0.45 were synthesized using solid-state reaction method. Except Bi2((Zn1/3Nb2/3)0.7Ti0.3)2O7 with single body-centered orthorhombic weberite phase, the orthorhombic weberite phase of the other compositions changes with sintering temperatures. End-centered orthorhombic weberite is the phase of the ceramics sintered at lower temperatures. With increasing sintering temperature, the end-centered orthorhombic weberite phase transforms into body-centered orthorhombic weberite phase gradually. Although the crystal structures are sensitive to the chemistries and synthesizing conditions, the dense ceramics of Bi2((Zn1/3Nb2/3)1-xTix)2O7 show similar dielectric permittivity ϵ of ∼160. Their temperature coefficients of capacitance TCC vary from −150 to −280 ppm/°C with increasing Ti content. High ϵ, low tanδ (<0.003) and low sintering temperature (∼950°C) make the Bi2((Zn1/3Nb2/3)1-xTix)2O7 ceramics are competitive candidates for multiplayer ceramics capacitors and low-temperature co-fired ceramics materials.