Date & Time
Wednesday, June 16, 2021, 11:30 AM - 11:40 AM
Growth of elastically-stiff, self-organized, 111-oriented (VNbTaMoW)N nanorods via reactive magnetron sputtering
FCSE Session Type
Session 6: Optical and functional properties of nanostructured coatings and metasurfaces

K. Tanaka1, H. Zaid1, C.V. Ciobanu2, M.E. Liao1, M.S. Goorsky1, Jenn-Ming Yang1, S. Kodambaka1, H. Kindlund1

1) Department of Materials Science and Engineering, University of California, Los Angeles

2) Department of Mechanical Engineering & Materials Science Program, Colorado School of Mines, Golden, CO 80401 USA

We demonstrate the growth of B1-structured, 111-textured, refractory high-entropy alloy nitride, (V0.21Nb0.18Ta0.19Mo0.21W0.21)N1.05, with lattice parameter of 0.4249 nm on MgO(001) and Al2O3(0001) via ultrahigh vacuum direct-current magnetron sputtering of a VNbTaMoW target in Kr/N2 gas mixtures at 1073 K. Interestingly, we observe an outgrowth of quasi one-dimensional nanorods with 3-fold symmetric facets, which we attribute to kinetic limitations of the sputter-deposition process exacerbated by the sluggish diffusion of the multicomponent adspecies and the preferential growth of {111} crystals. From in situ scanning electron microscopy observations of elastic buckling during compression of axially tapered (VNbTaMoW)N pillars, we determine elastic modulus to be 187 ± 70 GPa. Density functional theory (DFT) calculations reveal that the nitride alloy is stable in B1 structure despite significant concentration of the unstable B1-WN and B1-MoN with moduli higher than the stable parent binary nitrides (B1- VN, NbN, and TaN).