Effects of Li and Y co-doping on electrical properties and dielectric relaxation behavior of BCZT ceramics

• Published in: Journal of materials science. Materials in electronics 2022-03, Vol.33 (7), p.3822-3834
• Main Authors: Wang, Chang-Qun, Shu, Chun, Zheng, De-Yi, Luo, Shun
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Densification; Dielectric relaxation; Doping; Electrical properties; Ferroelectricity; Grain growth; Lead free; Materials Science; Optical and Electronic Materials; Perovskite structure; Perovskites; Piezoelectric ceramics; Piezoelectricity; Sintering; Solid phases; Temperature dependence; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-07573-z

In order to research the effects of Li and Y (Li/Y) co-doping on BCZT ceramics, lead-free (Ba 0.85 Ca 0.15 ) (Ti 0.9 Zr 0.1 ) + x Li 2 CO 3 + x Y 2 O 3 (abbreviated as BCZT-Li x Y x , x = 0, 0.1, 0.2, 0.3, and 0.4 mol%) piezoceramics were synthesized by traditional solid-state sintering method. The phase structure and microstructure of ceramic samples were researched through XRD and SEM. The electrical properties of ceramic samples were researched by piezoelectric, dielectric, and ferroelectric test instruments. The XRD spectrums indicate that ceramic samples have the perovskite structure. The SEM images show that the introduction of Li/Y in BCZT ceramics can promote grain growth and densification. The temperature-dependent dielectric performance testing results prove that BCZT-Li x Y x ceramic samples have apparent dielectric relaxation behavior. Moreover, co-doping Li/Y in BCZT ceramics can effectively decrease the sintering temperature from 1540 °C to 1400 °C and improve the electrical properties. The optimal electrical properties are obtained at x = 0.3 mol% ( d 33 = 526 pC/N, k p = 58%, ε r = 4724, tan δ  = 0.017, T c = 75.5 °C, γ  = 1.63, P r = 9.73 µC/cm 2 , E c = 2.10 kV/cm).