Atomic pair substitution in BN–C and GaP–Si solid solutions crystals studied by x-ray diffraction

This letter reports about crystal structure, lattice relaxation, synthesis, and phase stability of BN–C and GaP–Si solid solution crystals. The hypothesis of atomic pair substitution is discussed and x-ray diffraction (XRD) proof is provided for the replacement of AIIIBV atomic pairs with CIV pairs. Cubic BN–diamond solid solutions underwent lattice relaxation after phase transformation leading to atomic displacement disorder.

► Atomic structure of solid solution crystals of BN–C and GaP studied by X-ray diffraction.
► Substitution of pairs of B–N (Ga–P) atoms by C–C (Si–Si) proved.
► Lattice relaxation revealed metastability of phases.