INTERACTION BETWEEN POTASSIUM AND SULFUR-ATOMS AT THE IRON SURFACE

The interaction between sulphur and potassium adsorbed on the Fe(111) surface has been studied using Auger Electron Spectroscopy. Potassium adsorbed on the Fe(111)p(1x1)-S surface is thermally more stable than on the clean iron surface and the potassium coverage degree on the sul phur-precovered iron surface is greater. The shape of the potassium AE S line is the same for the clean and for the sulphur-precovered iron s urface, but the shape of the sulphur AES line changes significantly du e to potassium adsorption, indicating the reduction of the interaction between iron and and sulphur. The change of the character of the sulp hur AES spectrum after potassium adsorption, from molecular-like AES s pectrum to the atomic-like one, is attributed to the electron transfer from potassium to sulphur.