Electrical properties tailoring in Ni-particle-dispersed (Ba 0.95Ca 0.05)(Ti 0.96Zr 0.04)O 3 composites

• Published in: Materials chemistry and physics Vol. 126; no. 3; pp. 729 - 733
• Main Authors: Yang, Sui, Zhang, Hailong, Zhang, Su-Wei, Zhang, Bo-Ping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.04.2011
• Subjects: A. Ceramics; A. Composite materials; B. Sintering; D. Electrical properties; A. Ceramics; A. Composite materials; B. Sintering; D. Electrical properties
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2010.12.052

▶ Ni-particle-dispersed (Ba 0.95Ca 0.05)(Ti 0.96Zr 0.04)O 3 piezoelectric composites. ▶ Ni is not oxidized and BCTZ preserves perovskite structure. ▶ Relative dielectric constant increases with increasing Ni content. ▶ Piezoelectric constant decreases with increasing Ni content. Ni-particle-dispersed (Ba 0.95Ca 0.05)(Ti 0.96Zr 0.04)O 3 (BCTZ/Ni) piezoceramic composites were prepared via sintering at 1300 °C in industrial N 2 gas. Structural characterizations showed that the metallic Ni was not oxidized and the BCTZ preserved the perovskite structure. The Ni particles were uniformly distributed in the BCTZ ceramic matrix. The relative dielectric constant ɛ r of the BCTZ/Ni composites increased from 1362 to 3910 with increasing Ni content from 0 to 20 vol.%, which is explained by the Maxwell equation as well as the micro-capacitor model. The percolation theory of insulator–metal transitions is also applied to correlate the rapid increase of dielectric constant with Ni content. The piezoelectric constant d 33 gradually decreased from 230 to 50 pC N −1, giving a gradient profile of piezoelectric property. We demonstrate that the electrical properties can be effectively tailored by dispersing metal particles into piezoceramics.