Direction of electron transfer in FeNi alloy surface

Abstract

The direction of electron transfer in FeNi alloys was studied by an infrared technique comparing CO interaction with CuNi and CoNi alloy systems. The results were interpreted by the d-hole relationship of the metals and the saturation magnetization of alloy systems. An electron transfer from Fe to Ni in the FeNi alloy system is proposed, whereas no electron transfer between alloying components is believed to occur in the CoNi alloy system. A critical point for the FeCO interaction on the FeNi alloy surface was observed at 75 Fe25 Ni atom percent; a critical point for CuCO interaction on the CaNi alloy surface was previously found at 85 Cu15 Ni atom percent. No similar critical composition was found on the CONi alloy surfaces. Some of Uhlig's corrosion theory of surface passivity was applied to the calculation of critical composition. Infrared band shifts on the alloy surfaces are shown. Infrared absorption bands for CO on silica-supported metal alloy surfaces were determined in the region from 2200 cm −1 to 1600 cm −1.