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A high-precision reflection high-energy electron diffraction (RHEED) analysis of the in-plane lattice spacing of the surface during epitaxial growth of fcc Fe films on a Cu(100) single crystal substrate is presented. As a function of Fe coverage, initially the in-plane fcc Fe lattice spacing is found to decrease drastically until a minimum is reached, while at higher coverages the smaller equilibrium value for bulk fcc Fe (3.59 A), rather than the value of the Cu substrate (3.615 A), is approached. This proves that fcc Fe films on Cu(100) grow strain free and are non-pseudomorphous, contrary to earlier assumptions.

Mossbauer effect studies were carried out on CoxGa(1−x) alloys, on pure Ga and on CoGa3 and FeGa3 intermetallics by using 57Co and 57Fe probe atoms. 57Co source spectra showed broad absorption lines in CoxGa(1−x) indicating distribution in the quadrupole split values. The concentration dependence of the distribution reflected the formation of the high vacancy concentration in the Co sublattice at low x values. The results obtained for 57Fe absorbers suggested that the location of iron in the lattice is vacancy concentration dependent. At high vacancy concentration a large fraction of iron atoms change position and are populated in the Co sublattice.

Mossbauer effect studies of Pt 3− x Fe 1+ x fcc ordered alloys in the range 4.2 K T x = 0.16 to 0.28, are reported. The low-temperature spectra show several satellite lines which are related to different excess-Fe nearest-neighbor configurations. Experiments in external fields give information on the different local spin structure at different concentrations.

FCC (γ-) Fe(100)-films prepared by epitaxial growth in UHV on Cu(100)-films were investigated by Conversion Electron Mossbauer Spectroscopy (CEMS) at 295 K using a He-CH 4 flow-gas counter. The fcc structure of the Fe films was confirmed by LEED. The Mossbauer spectra clearly demonstrate that γ-Fe(100)-films are paramagnetic at 295 K. Depending on the Fe film thickness part of the Fe atoms exists in the α-Fe phase.

A simple electron-beam heated furnace is described which allows the controlled evaporation of small quantities of isotopes, particularly of 57Fe, for thin film deposition.