AFM data illustrating the composition of self-assembled sample systems and the selective wetting of Fe on the copolymer template. Micrograph of a sample system consisting of a sapphire substrate, copolymer template, and Fe nanodots showing the exposed nanofaceted substrate in the upper half and the Fe nanodot array in the lower half. From Sci. Adv. 1, e1500751 (2015).