Self-Organized Growth Of 111-Oriented (Vnbtamow)N Nanorods On Mgo(001)

Refractory high-entropy alloy nitride, (VNbTaMoW)N, layers are grown on single-crystalline MgO(001) via ultrahigh vacuum direct current magnetron sputtering of a VNbTaMoW target in Kr/N-2 gas mixtures at 1073 K. X-ray diffraction, scanning and transmission electron microscopy, and energy dispersive X-ray spectroscopy characterizations revealed the formation of B1 -structure d, 111-textured (V0.21Nb0.18Ta0.19Mo0.21W0.21)NLos with lattice parameter a = 0.4249 nm. The alloy nitride film exhibits dense columnar microstructure near the substrate-film interface with coherent 001 grain growth limited to a few tens of nanometers, followed by an outgrowth of quasi one-dimensional nanorods with 3-fold symmetric facets. We attribute the self-organized growth of rather unusual 111-textured nanorods on isostructural MgO(001) to kinetic limitations of the sputter-deposition process exacerbated by the sluggish diffusion of the multicomponent adspecies and the preferential growth of {111} crystals.