Percolation-induced low frequency plasmonic state in metal granular composite materials

¹Graduate School of Education, Hiroshima University, Higashi-Hiroshima, 739-8524, Japan

²National Institute of Technology, Tokuyama College, Shunan, 745-8585, Japan

Adv. Mater. Lett., 2018, 9 (7), pp 476-480

DOI: 10.5185/amlett.2018.2053

Publication Date (Web): Jun 14, 2018

Copyright © IAAM-VBRI Press

E-mail: tsutaok@hiroshima-u.ac.jp

Abstract

Low frequency plasmonic (LFP) state induced by the electrical percolation of metallic particles has been investigated for metal granular composite materials containing Cu, Ni₄₇Fe₅₃ and Co₅₀Fe₅₀ microparticles. In these composites, a conductivity jump due to electrical percolation takes place at different particle volume fraction j; a conductive state is established above the percolation threshold j_C. The j_C is 0.16 for Cu, 0.61 for Ni₄₇Fe₅₃, and 0.76 for Co₅₀Fe₅₀ composites, respectively. In the Cu composite, the LFP state takes place in the conductive state just above j_C. However, in the Ni₄₇Fe₅₃ composite, the LFP state is established at j = 0.90; the LFP state couldn’t be observed in the Co₅₀Fe₅₀ one. Hence, a non-plasmonic conductive state can exist in the percolated state; the LFP state can be established in the conductive state with about 1.0 S/cm of the conductivity value. 

Keywords

Metal granular composite, low frequency plasmonic state, permittivity, conductivity.