Prediction of coherent interfaces between diamond and clathrate structures

Abstract

Diamond (or its binary zincblende variant)-type structure can form coherent interface with clathrate type II via the common transitional layer known previously as a $(3\times 3)$-dimer-stacking fault (DS) reconstruction of the (111)-diamond surface. The generic $\sim 11\%$ lattice misfit can be eliminated in multicomponent heterostructures such as Ge(diamond)/CsSn(clathrate) or InN(zincblende)/Ge(clathrate). Interface models subjected to ab-initio molecular dynamics annealing are stable up to the temperatures approaching melting point of the constituent systems, and in some studied cases the diamond/clathrate bonding is stronger than the intra-clathrate bonding, as evidenced by simulated crack experiments. Composition-calibrated lattice-matching can stabilize even metastable clathrates as epitaxially grown films on the diamond/zincblende substrate.