Shape-controlled electrodeposition of tin crystals from Sn(II)-fluoroborate solutions

The shape evolution of mesoscopic tin crystals electrodeposited on boron-doped diamond (BDD) substrates is described as a function of the ion concentration and deposition potential. Concentrations of 5-100 mM Sn(II) in 1 M fluoroboric acid have been explored and electron micrographs of the deposited crystals used to characterise the different shapes and sizes of the crystals obtained. Low concentrations and low overpotentials result in faceted cuboid-shaped crystals while higher concentrations and deposition potentials yield highly complex and fractal-like structures with high surface energies. These crystals can be used as model systems for studying mesoscopic superconductivity, or as a template for core-shell structures if plated with a second metal.