Nature 502, 215–218 (2013)

Credit: © 2013 NPG

By displaying structural order yet simultaneously lacking periodicity, the counterintuitive nature of quasicrystals has fascinated materials scientists for three decades. Perhaps unsurprisingly, however, quasiperiodic order is rare and is restricted to a relatively small set of specific materials. Moreover, strategies for expanding this class typically focus on synthetic approaches seeking to expand the structural phase diagram of bulk intermetallic materials. Wolf Widdra and colleagues now present an elegant alternative, which is to induce quasicrystallinity in thin films of an otherwise periodic material, by exploiting the structural mismatch with a substrate with different symmetry. The material they choose for their investigation is perovskite barium titanate BaTiO3. They find that by depositing it on a platinum substrate with three-fold symmetry, the barium titanate can be made to adopt a quasicrystalline dodecahedral structure. All of which suggests that interface-driven formation of ultrathin quasicrystals may open the way to a wider family of quasicrystalline oxides with intriguing physical properties.