Our latest paper, entitled “Electric-field-controlled reversible order-disorder switching of a metal tip surface” has been published in Physical Review Materials.
In this work led by Ludvig de Knoop and Mikael Juhani Kuisma, the deformation at the very tip of a gold nanocone was studied on the atomic level using TEM (transmission electron microscopy). When a large electric field is applied, the topmost atomic layers of the cone make a reversible switch from a crystalline to a disordered state. When the electric field exceed a threshold of about 25V/nm, gold atoms can be evaporated from the tip at room temperature. These observations were also studied using ab initio molecular dynamics (AIMD) simulations, which were in excellent agreement with the measured data.
The samples for these experiments were fabricated during one of my last work days at Chalmers, using our transfer protocol to decorate a gold wire with a pattern of nanocones for use in the TEM experiments.