Single crystal growth of small-angle-grain-boundary-free Mg2Si via vertical Bridgman method

•Mg2Si single crystals were grown via vertical Bridgman method using BN coated pBN crucible.•The BN coated pBN provided a non– wetting surface to the molten Mg2Si.•The grown Mg2Si were a small-angle-grain-boundary-free crystals.•The FWHM of 44–51 arcsec was obtained by X-ray rocking curve measurement at 400 reflection.