Published online by Cambridge University Press: 15 February 2011
A new epitaxial CoSi2 phase has been synthesized on Si(111) by molecular beam epitaxy (MBE) at room temperature (RT). Structural investigations revealed, that films grown onto an ultrathin CoSi2 template crystallize with the CsC1 structure with 50% vacancies on the cation lattice. The same is true for codeposited films nucleating from the amorphous phase at very low annealing temperatures (100–200 °C). Upon annealing a gradual transition to the stable bulk phase with the CaF2 structure takes place. For films grown onto a template, some grains of (CsCl)Co0.5Si remain stable up to at least 550 °C, while the films grown without a template are fully transformed.