New method for the preparation of S doped Fe samples characterized by AES and TOF-SIMS depth profiling

A new method for the preparation of sulfur (S) doped iron (Fe) samples is presented. The required amount of S in Fe is obtained by allowing the vaporized form of S to diffuse into a Fe sample (10 mm diameter, 0.5 mm thick) kept at a temperature of 750 K. Depth profile analysis using Auger Electron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) showed that the method is reproducible and can be used for the preparation of samples with different S concentrations. It was also found that S deposited onto Fe forms the desired FeS phase, which will prevent S from evaporating when the sample is annealed. Prepared samples were annealed to obtain homogeneity of S in Fe, after which the amount of S in the respective samples was determined by quantitative TOF-SIMS. The outcome of the results suggests the application of this method to other high melting point host and low melting point dopant systems. Copyright © 2014 John Wiley & Sons, Ltd.