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Colossal permittivity in percolative ceramic/metal dielectric composites

2015; Elsevier BV; Volume: 663; Linguagem: Inglês

10.1016/j.jallcom.2015.12.171

1873-4669

Haiwei Du, Xi Lin, Han Zheng, Bo Qu, Yanqiu Huang, Dewei Chu,

Ferroelectric and Piezoelectric Materials

Dielectric capacitor, as an essential building block, is ubiquitously used in many electronic and energy storage devices. With the development of modern electronics, dielectric materials with large capacitance, low dielectric loss and high reliability are highly desired, and research progress on various materials has been triggered for meeting the requirement of capacitor usage. Particularly, percolative composites in which metal fillers are dispersed in insulator matrix such as ceramic and polymer have attracted significant interests from both scientific and technologic perspectives. Among these materials, a giant permittivity up to 105-106 is achieved after the addition of metal particles in a composite without precise processing technology and capacitors based on this material can be potentially developed. The corresponding mechanism is based on percolation theory, demonstrating that the conductive pathway or network forms after metal content exceeds a critical value. The interfacial polarization induced by the increased local electric field at the interface between conductive phase and insulating phase is dominantly responsible for the permittivity enhancement. In this review, the recent advance in ceramic/metal composites (CMCs) with various metal fillers is reviewed from the viewpoint of dielectric ceramic materials. The remaining challenges, diverse applications and future prospect are also presented.