Microstructure and properties of (Ba_0.85Ca_0.15)(Zr_0.08Ti_0.9Sn_0.02)O₃ lead-free ceramics modified by Bi₂O₃

ABSTRACT

To get excellent electrical properties of lead-free piezoelectric ceramic (Ba_0.85Ca_0.15)(Zr_0.08Ti_0.9Sn_0.02)O₃ [BCZTS], Bi₂O₃ was doped to modify BCZTS. The microstructure, phases and electrical properties were investigated by XRD, SEM and ferroelectric test instrument, respectively. The experimental results indicate that the ceramics have pure perovskite structure with 0–0.08 wt.% Bi₂O₃, indicating that the Bi₂O₃ diffused into the lattice of BCZTS. And when the content of Bi₂O₃ reaches to 0.06 wt.%, homogenous microstructure and no pores can be found in ceramic. The ceramic has optimized properties of d₃₃ = 430 pC/N, k_p = 49.1%, ϵ_r = 3998, tan δ = 1.3%. Furthermore, the Curie temperature (T_c) increases firstly and then decreases as increasing the doping amount of Bi₂O₃. The P-E loops for the ceramics are observed and the value of Pr and Ec is 8.08uC/cm² and 3.45 kV/cm under 35 kV/cm, respectively.

KEYWORDS:

• Lead-free piezoelectric ceramic
• Curie temperature, Bi₂O₃ doping
• piezoelectric properties

Funding

This work was supported by the Industrial Research Projects of Guizhou Province of China [No.qian ke he GY (2013) 3027], the Special Fund Project in Guizhou Province of Industry and Information Technology Development-the 3rd batch of Technological Innovation Project [No.2016056], and a joint fund of Guizhou University and Science and Technology Department of Guizhou Province of China [No.qian ke he LH (2015) 7650].