Pseudo-tenfold twins in a new metastable chromium carbide and associated growth morphologies

Abstract
A new metastable chromium carbide Cr3C2-x, with a filled Re3B type structure, is formed during the crystallization of C-rich amorphous Cr–C alloys. Its crystals show tenfold twinning with different growth morphologies: faceted, dendritic, dense with tip splittings. A structural model of the twin boundaries, which agrees well with electron diffraction patterns and high-resolution electron microscopy images, is described.