TY - JOUR
T1 - Enhanced high permittivity BaTiO3-polymer nanocomposites from the cold sintering process
AU - Sada, Takao
AU - Tsuji, Kosuke
AU - Ndayishimiye, Arnaud
AU - Fan, Zhongming
AU - Fujioka, Yoshihiro
AU - Randall, Clive A.
N1 - Funding Information:
ACKNOWLEDGMENTST.S. would like to thank the Kyocera Corporation for funding his fellowship, enabling his time as a visiting scientist at the Pennsylvania State University. A.N., Z.F., and C.A.R. were partially supported by the AFOSR (Grant No. FA9550-19-1-0372). The authors also wish to thank the staffs of the MCL for aid in sample preparation and in maintaining electrical measurement facilities. They also thank Joanne Aller for helping in proof reading and formatting this publication.
Publisher Copyright:
© 2020 Author(s).
PY - 2020/8/28
Y1 - 2020/8/28
N2 - The dielectric property relations of a series of BaTiO3-polymer composites with a uniquely high-volume fraction of ceramic [(1 - x)BaTiO3-x polytetrafluoroethylene (PTFE), with volume fractions x = 0.025, 0.05, 0.1, and 0.2] are studied. Such high-volume fraction of the BaTiO3 phase is achieved by using the cold sintering process, as it enables a single-step densification of oxides at an extremely low temperature; typically, the volume fractions from other processing methods are limited to ceramic filler volume fractions of ∼0.6. Microstructural and resistivity analyses suggest that the optimal range of the polymer content to effectively enhance the functions is x = 0.05, as higher volume fractions of the polymer hinder the densification of the ceramic. The composite exhibits improved properties such as lower loss tangent, higher resistivity, and high permittivity that vary systematically with x following an empirical mixing law. Here, we consider the composite mixing law trends and the changes to properties, which indicate that size effects are also being induced in the dielectric response, including shift of Tc, broadening of transition, and reduction of permittivity with respect to volume fraction of the PTFE. Our findings provide a new and simple strategy for the fabrication of ceramic-polymer composites with extremely high relative permittivities and resistivities, and these observations all point to a route that can allow us to engineer new types of advanced dielectric materials.
AB - The dielectric property relations of a series of BaTiO3-polymer composites with a uniquely high-volume fraction of ceramic [(1 - x)BaTiO3-x polytetrafluoroethylene (PTFE), with volume fractions x = 0.025, 0.05, 0.1, and 0.2] are studied. Such high-volume fraction of the BaTiO3 phase is achieved by using the cold sintering process, as it enables a single-step densification of oxides at an extremely low temperature; typically, the volume fractions from other processing methods are limited to ceramic filler volume fractions of ∼0.6. Microstructural and resistivity analyses suggest that the optimal range of the polymer content to effectively enhance the functions is x = 0.05, as higher volume fractions of the polymer hinder the densification of the ceramic. The composite exhibits improved properties such as lower loss tangent, higher resistivity, and high permittivity that vary systematically with x following an empirical mixing law. Here, we consider the composite mixing law trends and the changes to properties, which indicate that size effects are also being induced in the dielectric response, including shift of Tc, broadening of transition, and reduction of permittivity with respect to volume fraction of the PTFE. Our findings provide a new and simple strategy for the fabrication of ceramic-polymer composites with extremely high relative permittivities and resistivities, and these observations all point to a route that can allow us to engineer new types of advanced dielectric materials.
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U2 - 10.1063/5.0021040
DO - 10.1063/5.0021040
M3 - Article
AN - SCOPUS:85090090880
VL - 128
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 8
M1 - 084103
ER -