GROUND-STATE OF ELECTRORHEOLOGICAL FLUIDS FROM MONTE-CARLO SIMULATIONS

We use Monte Carlo simulations to investigate the ground state of electrorheological (ER) fluids in a strong electric field. Our results suggest a body-centered tetragonal (bct) lattice with conventional Bravais vectors a1 = square-root 6ax, a2 = square-root 6ay, and a3 = 2az where a is the radius of dielectric spheres and the z axis is the direction of the applied electric field. This bct lattice can be regarded as a compound of chains of class A and class B where chains of class B are obtained from chains of class A by shifting a distance of a in the z direction. For typical ER systems, this bct structure can be formed at room temperature.