Enhanced the dielectric relaxation characteristics of BaTiO3 ceramic doped by BiFeO3 and synthesized by the microwave sintering method

Abstract

(1-x) BaTiO3-x BiFeO3 ((1-x) BT-x BFO) (x = 0, 0.01, 0.03, 0.06, 0.1) ceramics with 0.15 wt% SiO2 additive were synthesized by microwave sintering (MWS) and conventional sintering (CS). The crystal structure, micromorphology, dielectric relaxation behavior and ferroelectric properties of (1-x) BT-x BFO-0.15 wt% SiO2 ceramics were investigated in detail. The results show that a phase structure transforms from a tetragonal phase to a pseudo-cubic phase for all samples and MWS method contributes to refine the grain and make the grain size more uniform. Moreover, a transition undergoes gradually from normal ferroelectric to relaxor ferroelectric is observed. The diffuseness coefficient γ of (1-x) BT-x BFO-0.15 wt% SiO2 ceramics increases with increasing BFO content and sintered by MWS when x ≤ 0.06. The maximum diffuseness coefficient (γ = 1.69) can be obtained at x = 0.06 for MWS ceramic. Polarization-electric (P-E) hysteresis loops are gradually slimmer as x increasing, and a slimmer P-E hysteresis loops is obtained by MWS method. The remnant polarization and coercive field reduce using BFO dopant and MWS method, which also suggests that the dielectric relaxation behavior is strengthened. These results indicate that BFO dopant and MWS technique are both effective methods to improve the relaxation behavior of BT-based ceramics.