Substrate orientation effects on the nucleation and growth of the M(n+1)AX(n) phase Ti2AlC

• The M(n+1)AX(n) (MAX) phases are ternary compounds comprising alternating layers of a transition metal carbide or nitride and a third "A-group" element. The effect of substrate orientation on the growth of Ti2AlC MAX phase films was investigated by studying pulsed cathodic arc deposited samples grown on sapphire cut along the (0001), (10 (1) over bar0), and (1 (1) over bar 02) crystallographic planes. Characterization of these samples was by x-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. On the (10 (1) over bar0) substrate, tilted (10 (1) over bar8) growth of Ti2AlC was found, such that the TiC octahedra of the MAX phase structure have the same orientation as a spontaneously formed epitaxial TiC sublayer, preserving the typical TiC-Ti2AlC epitaxial relationship and confirming the importance of this relationship in determining MAX phase film orientation. An additional component of Ti2AlC with tilted fiber texture was observed in this sample; tilted fiber texture, or axiotaxy, has not previously been seen in MAX phase films.

Nyckelord

TECHNOLOGY

TEKNIKVETENSKAP

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)