SEM images of produced agglomerate structures: single sphere (panel a); two particles are linearly arranged (2 linear: panel b); three particles are linearly arranged (3 linear: panel c); three particles are arranged in a triangular shape (triangle: panel d); four particles are linearly arranged (4 linear: panel e); four particles are arranged in a diamond shape (diamond: panel f). The magnification of the images is 36 K, and each sphere has a diameter of 1 μm. In panel f a slight deviation from the ideal structure with perfect touching of all spheres in visible.