High resolution x-ray diffraction studies of short-period CdTe/MnTe superlattices

We have investigated the elastic properties of epitaxial MnTe layers using triple axis high resolution x-ray diffraction and reciprocal space mapping. A series CdTe/MnTe superlattices (SLs) grown by molecular beam epitaxy and nearly strain compensated, were deposited on [001] Cd_1-xZn_xTe substrates. In order to obtain the MnTe content of these SLs without an a priori knowledge of the elastic properties of cubic MnTe, annealing experiments were performed to interdiffuse the individual layers into a mixed Cd_1-xMn_x Te alloy layer. For a precise analysis of the data, it was found to be important to determine the in-plane strain of the superlattice layers using reciprocal space maps around symmetric and asymmetric reciprocal lattice points. The value for the Poisson ratio of zinc-blende MnTe was determined to be v=C₁₁/2C₁₂=0.77±0.15.