Structural and elastic properties of strained Mg1−xSrxSe revealed

• We model the disordered alloy at several compositions by DFT calculations.
• Disorder is described by Special QuasiRandom Structures (SQS).
• Structural and elastic properties are determined.
• Band gap bowing is also calculated at the DFT level.

For the first time, detailed first principle calculations within the generalized gradient approximation (GGA) are performed to study electronic structure and elastic properties of Mg1−xSrxSeMg1−xSrxSe ternary alloys at various concentrations of Sr atoms. Band gap energies are predicted for the ternary alloys with x=0.47 concentration to have a minimum energy gap of 2.07 eV. From our calculations the alloy closely follows Vegard's law with a small bowing parameter of −0.0103 Å. Calculated elastic constants are given along with other elastic properties for the ternary alloys. Among the examined structures, Sr-rich alloys display a large Poisson's ratio indicating a stretch densifying property. The resemblance of the calculated lattice parameter at low Sr concentration to that of InAs suggests that MgSrSe alloys can be experimentally grown on indium arsenide.