Field ion microscope observation of tungsten surface processed in ethanol

An attempt has been made to observe ethanol molecules on tungsten needle by field ion microscope (FIM). An electrochemically polished tungsten needle was dipped in ethanol with and without application of positive bias. FIM images which exhibited elongated spots were obtained with the samples processed with the positive bias. Without the positive bias, the elongated spots were not observed. It was suggested that these spots were originated from the ethanol molecules. Field emission microscopy observations were also conducted to investigate the processed tip surface.