Longitudinal and transversal piezoresistive response of granular metals

Abstract

In this paper, we study the piezoresistive response and its anisotropy for a bond percolation model of granular metals. Both effective medium results and numerical Monte Carlo calculations of finite simple cubic networks show that the piezoresistive anisotropy is a strongly dependent function of bond probability p and of bond conductance distribution width Δg. We find that piezoresistive anisotropy is strongly suppressed as p is reduced and/or Δg is enhanced and that it vanishes at the percolation thresold p=p_c. We argue that a measurement of the piezoresistive anisotropy could be a sensitive tool to estimate critical metallic concentrations in real granular metals.

14 pages, 7 eps figures