FE-57 MOSSBAUER SPECTROSCOPIC STUDY ON SURFACE PRODUCTS OF THIN IRON PLATES EXPOSED TO AMBIENT ATMOSPHERE AS A MEANS OF ENVIRONMENTAL MONITORING

Conversion electron and transmission Mossbauer spectroscopy were applied to the analysis of thin iron plates exposed to the ambient atmosphere. The degree of corrosion of the iron plates was classified into three categories according to the kind and thickness of rust evaluated by Mossbauer spectra. The severe corrosion took place in seaside and roadside areas. The medium corrosion was observed in urban areas, and the weak corrosion occurred in suburban and mountainous areas. This fact implies that the surface products of iron plates can successfully reflect the ambient atmosphere to which the plates were exposed.