Fe-contacts on InAs(100) and InP(100) characterised by conversion electron Mِssbauer spectroscopy

We have grown 4 nm thin films of 57Fe on InAs(100) and InP(100) surfaces by use of MBE and studied the samples by 57Fe conversion electron Mössbauer spectroscopy. In the case of InAs, the Mössbauer spectrum showed a sextet due to α-Fe and a further magnetically split component with slightly smaller hyperfine field, which is attributed to interface components. This result indicates that there is a relatively sharp interface between Fe and InAs. On the contrary, the spectrum of the InP sample showed a sextet with very broad lines and a smaller average hyperfine field. This suggests a strong chemical reaction between iron and the substrate, which results in the formation of a poorly crystalline phase.