Oxygen-covered tungsten crystal shape: Time effects, equilibrium, surface energy and the edge-rounding temperature

► Temperature-dependent equilibrium crystal shape of oxygen-covered tungsten microcrystal. ► Specially designed ultrafast crystal quenching setup: 6000 K/s. ► Edge-rounding transition occurs between 1300 K and 1430 K. ► The ratio of surface free energies gamma(111)/gamma(211) is determined as a function of temperature.