Connecting packing efficiency of binary hard sphere systems to their intermediate range structure

H. Yuan (1) , Z. Zhang (2) , Walter Kob (3, 1) , Y. Wang (1)

1 Shanghai Jiao Tong University [Shanghai]
2 Xjtu - Xi'an Jiaotong University
3 L2C - Laboratoire Charles Coulomb

Using computed x-ray tomography we determine the three dimensional (3D) structure of binary hard sphere mixtures as a function of composition and size ratio of the particles q. Using a recently introduced four-point correlation function we reveal that this 3D structure has on intermediate and large length scales a surprisingly regular order, the symmetry of which depends on q. The related structural correlation length has a minimum at the composition at which the packing fraction is highest. At this composition also the number of different local particle arrangements has a maximum, indicating that efficient packing of particles is associated with a structure that is locally maximally disordered.

Domaines: Mécanique statistique [cond-mat.stat-mech]; Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

H. Yuan, Z. Zhang, Walter Kob, Y. Wang. Connecting packing efficiency of binary hard sphere systems to their intermediate range structure. Physical Review Letters, 2022, 127 (27), pp.278001. ⟨10.1103/PhysRevLett.127.278001⟩. ⟨hal-03522429⟩