Enhanced dielectric properties of Ca0.9Sr0.1Cu3-yZnyTi4-xBxO12 ceramics by modifying grain boundary response

• Published in: Materials chemistry and physics 2021-03, Vol.261, p.1, Article 124207
• Main Authors: Xu, Zunping, Chen, Yi, Cheng, Nanpu
• Format: Article
• Language: English
• Subjects: CaCu3Ti4O12; Ceramics; Co-substitution; Dielectric loss; Dielectric properties; Dielectric strength; Doping; Electrical properties; Frequency stability; Grain boundaries; Grain growth; Grain size; Microstructure; X-ray diffraction
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2020.124207

Ca0.9Sr0.1Cu3-yZnyTi4-xBxO12 ceramics (0.01 ≤ x ≤ 0.07, y = 0 and 0.05) were prepared using the citrate precursor process and sintered at 1100 °C for 3 h. X-ray diffraction (XRD) has confirmed that CaCu3Ti4O12 ceramics with single phase can be prepared for a short-term sintering. The results of XRD and Raman reveals the existence of secondary phase as x = 0.07. The energy dispersive spectrometer confirms the presence of Cu-rich phase at grain boundary, which leads to a weakened dielectric properties. B3+ doping can speed the grain growth, whereas Zn2+ doping decreases grain size slightly and high dense microstructures were observed. The introduction of Zn2+ leads to an increase of grain boundary resistance, a decrease of dielectric loss and an enhancement of frequency stability of dielectric properties. Enhanced dielectric properties with dielectric constant of ~13410 and dielectric loss of ~0.038 were observed for the sample at x = 0.04 and y = 0.05. Moreover, the nonlinear electrical characteristics are enhanced with proper concentration of Sr, B and Zn additions. The present results indicate that the improved dielectric properties of doped CCTO ceramics are mainly attributed to the improved microstructure and the modified grain boundary response. •Doped CCTO powders were synthesized using the citrate precursor process.•Dense microstructure can be obtained for doped CCTO sintered for a short-term.•Dielectric properties and grain boundary resistance are improved.•Co-doped CCTO shows good stability of dielectric properties.