The epitaxial growth of thin CaGe2 films with reactive deposition epitaxy (RDE) on Ge(1 1 1) substrates is described. The films consist in general of a mixture of the known trigonal rhombohedral tr6 modification and a hexagonal h2 modification of CaGe2 containing two Ca and two buckled Ge layers per unit cell in a twofold stacking sequence whose formation appears to be favored by strain. Epitaxial layers of both polytypes show remarkably higher crystalline quality compared to epitaxial CaSi2 films grown on silicon substrates. The tr6 modification is found to be unstable in air in contrast to the h2 modification. «
The epitaxial growth of thin CaGe2 films with reactive deposition epitaxy (RDE) on Ge(1 1 1) substrates is described. The films consist in general of a mixture of the known trigonal rhombohedral tr6 modification and a hexagonal h2 modification of CaGe2 containing two Ca and two buckled Ge layers per unit cell in a twofold stacking sequence whose formation appears to be favored by strain. Epitaxial layers of both polytypes show remarkably higher crystalline quality compared to epitaxial CaSi2 fil... »