A field ion microscope study on the surface reaction of tungsten with n-octanol under an applied positive voltage: Reaction conditions for the “splitting” of (110) plane

An interesting phenomenon, "splitting" wherein the central (110) plane of a tungsten tip is divided into two parts by a groove made on the [001] zone line when an appropriate electrical pule with a height between +5 and 10 V is applied one or more times while the tip is immersed in n-octanol has been shown to result from a reaction which proceeds in a specific direction on the tip cap. The sufficient conditions of the pulse in order for the splitting to occur are a rise time < 150 ns and a duration, or a total accumulated duration if the pulse is applied repeatedly, > 3.2 s. The splitting was always accompanied by the reduction in the radius of curvature of the tip cap.