Effect of interface behavior on dielectric properties of ferroelectric-dielectric composite ceramics

• Published in: Journal of alloys and compounds 2019-11, Vol.809, p.151712, Article 151712
• Main Authors: Wang, Wei, Zhang, Mingwei, Xin, Le, Shen, Shiting, Zhai, Jiwei
• Format: Article
• Language: English
• Subjects: Ceramics; Curie temperature; Dielectric properties; Ferroelectric materials; Ferroelectricity; Grain size; High tunability; Ion diffusion; Ions diffusion; Low loss; Phase composition; Size effects
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.151712

Ba0.4Sr0.6TiO3–ZnAl2O4 composite ceramics have been synthesized by a solid-state sintering process. The relationship among phase composition, microstructures and dielectric properties has been investigated. For this composite system, high tunability of 31.50% (at 30 kV/cm), high Q value of 707 (at 3.683 GHz) and appropriate permittivity of 178 were achieved simultaneous at x = 70 wt%. With increasing ZnAl2O4 content, the quality value is gradually enhanced, reflecting the composite effect at high ZnAl2O4 content. Meanwhile, Curie temperature shifts towards higher temperature, because of the low ion diffusion between ferroelectric and dielectric phase along with grain size effect in the selected system. Dielectric diffuseness characteristic was studied by scaling empirical formula, which confirms the low ion diffusion between the BST and ZnAl2O4 phases. •TC shifts towards high temperature, which is different from other systems reported, is conducive to gain large tunability.•There is lower ions diffusion between ferroelectric BST and dielectric ZnAl2O4.•Low ions solubility makes an obvious composite effect under high concentrate dielectric.•The permittivity is effectively reduced, but the Q value and tunability are still high..