Fig. 4. Effect of patch size J.
(A) Calculated dipolar magnetic energy as a function of θ for different patch sizes. The minimum found at θ = 90° for an isotropic particle is relocated to θlmin = 93°, 97°, 101°, 105°, and 109° for J = 0.1, 0.2, 0.3, 0.4, and 0.5, respectively. (B) Measured and calculated values of distance δ increasing as a function of J, i.e., the fraction of the surface covered by the metal patch. Error bars represent the SD of the location of the satellite particle on the surface of a patchy particle. This is due to the inherent surface diffusion of the satellite on the core particle. (C) From bottom to top, images of AB Y supraparticles of varying structure as obtained by increasing iron patch size. δ ranges from 0.05 μm for an isotropic core particle to 1.1 μm for a Janus particle. The symmetry point group of the supraparticle changes from D∞h to C2v upon increasing the patch size from J = 0.0 to 0.5. Scale bar, 2.0 μm.