title: Structural transition in bidispersed electrorheological fluids.
abstract: We present results from finite element calculations on electrorheological fluids consisting of bidispersed dielectric microspheres and nanoparticles suspended in liquid, with one type much smaller than the other. The face-centered-cubic (fcc) structure of the larger microspheres is shown to be the ground state when the volume concentration of the nanoparticles is between 3-5 %. This is in contrast to the usual situation in which the body-centered-tetragonal (bct) structure is the lowest-energy state. As a function of the nanoparticles' concentration, the bct-fcc structural transition occurs when the nanoparticles' dielectric constant exceeds a threshold value, leading to the electrostatic energy curves of the two structures crossing each other.
authors.affiliation: Department of Physics and Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Xianxiang
authors.initials: X
authors.lastname: Huang
authors.forename: Wing Yim
authors.initials: WY
authors.lastname: Tam
authors.forename: Ping
authors.initials: P
authors.lastname: Sheng