The MBE growth and interface formation of thin Ca0.43Sr0.57F2 films deposited on GaAs(100) has been studied using synchrotron radiation photoemission spectroscopy. Surface sensitive core level spectra and RHEED suggest an extended fluorine-deficient interface for growth at 325°C. Annealing experiments confirm the loss of fluorine at temperatures equal to or greater than 325°C. As 3d spectra did not provide evidence for Ca-As bonds. The fluoride interface formed under these conditions apears to be atomically abrupt but contains a considerable amount of fluorine vacancies. Despite the reduction in interfacial strain by using a lattice matched mixed fluoride of composition Ca0.43Sr0.57F2, RHEED images indicate growth of epitaxial islands.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Mathematical Physics
- Condensed Matter Physics