Study of Fe−Ti and Fe−TiN interfaces by conversion electron Mössbauer spectroscopy

Titanium and titanium nitride-iron interfaces obtained by PVD coated thin films of Ti and TiN onto argon plasma etched iron substrates at various temperatures and negative bias were studied by use of CEMS. It was found that intermixing to Ti with Fe resulted in the appearance of an amorphous FeTi1−x phase. Furthermore, a comparison of CEM spectra of samples before and after heating in UHV has shown rather strong influence of thermal treatments on Fe/Ti as well as Fe/TiN interfaces.

Conversion electron Mössbauer study of vacuum and thermally treated vivianite

Natural vivianite samples were studied by Mossbauer transmission and conversion electron spectroscopy. The intensities of ferrous doublets in vivianite and the widths of the resonance lines depend strongly on the origin of the samples, on their preparation history, and on exposures in vacuo as well as on thermal treatments. An additional ferrous doublet appearing in samples after vacuum treatment can be ascribed to a tetrahydrate phosphate phase appearing at the surface due to dehydration. Heating at 413 K in dry air for periods of 15–240 min causes a higher oxidation and decomposition rate at the surface region than in the bulk of vivianite. All results do not confirm the assumption publis…

Optimization of a conversion electron Mössbauer spectroscopy gas flow He/CH4 proportional counter

A new detector for CEMS has been built and optimized with respect to the statistical quality of spectra obtained. The optimization has been performed by measuring Mosbauer and pulse height spectra at in- and off-resonance. Single channel analyzer settings were calculated by a new optimization routine. A comparison of different detector designs has been performed using the statistical utility rate of spectra obtained from a stainless steel foil. A procedure for determining optimal operating parameters for ICEMS gas flow proportional counters is proposed.

Poster contributions