The effect of nano-sized superparamagnetic particles on the dielectric constant of polyimide

Autor:	Chongdo Park, Y. H. Jeong, J. H. Kang
Rok vydání:	2006
Předmět:	Permittivity Condensed Matter::Materials Science Materials science Composite number General Physics and Astronomy Dielectric Dielectric thin films Composite material Spectroscopy Nano sized Polyimide Superparamagnetism
Zdroj:	Europhysics Letters (EPL). 74:903-908
ISSN:	1286-4854 0295-5075
Popis:	We propose that dynamically induced internal fields be utilized in obtaining materials with low dielectric constant at high frequencies. We also demonstrate the validity of the proposal by measuring the effective dielectric constant of polyimide dispersed with nano-sized Ni0.6Zn0.4Fe2O4 particles. The dielectric constant of a polyimide composite measured at 1 MHz increases as a function of Ni0.6Zn0.4Fe2O4 contents when the diameter of the embedded particles is approximately 20 nm. On the other hand, the measured dielectric constant of a composite containing superparamagnetic particles of diameter approximately 6 nm showed much smaller value than that of pure polyimide. These contrasting behaviors indicate that the induced internal fields are in operation, in reducing the dielectric constant, for a material with superparamagnetic particles.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::9005c256ea67d73e7355f4096a67b33f https://doi.org/10.1209/epl/i2005-10586-y Zobrazit plný text záznamu