Dy₂O₃ Doped (Ba_0.85Ca_0.15)(Ti_0.90Zr_0.10)O₃ Ceramics

Abstract

(Ba_0.85Ca_0.15)(Ti_0.90Zr_0.10)O₃ (BCTZ)+ xwt%Dy₂O₃(x = 0–0.20) ceramics were prepared by conventional solid-state process, and the effects of Dy₂O₃ on the microstructure and the electrical properties were investigated. X-ray diffraction pattern confirmed that the BCTZ ceramics exhibit tetragonal structure, and stable solid solutions between BCTZ and Dy₂O₃ were well established in the range investigated. SEM images show that the addition of Dy₂O₃ restrains abnormal grain growth and leads to the formation of homogeneous microstructures during sintering. Dy³⁺ occupies B-site at x = 0–0.15, and A-site at x = 0.20 respectively. A-site occupation of Dy³⁺ into BCZT ceramic facilitates the ferroelectric domains reorientation and thus improves the piezoelectric properties significantly from 315pC/N(x = 0) to 425pC/N(x = 0.20). The corresponding planar electromechanical coupling factor at x = 0.20 was 49.1%. The A-site occupation(x = 0.2) also exhibits superiority to the improvement of dielectric properties and ferroelectric properties for BCZT ceramics (ϵ₃₃ = 3264 at 1 kHz, 2Pr = 28.4μC/cm², 2Ec = 5.28 kV/cm).

Keywords:

• Dy₂O₃
• BCTZ
• piezoelectric
• amphoteric ions
• dielectrics