Structure, stability, and mechanical properties of epitaxial W/NbN superlattices Academic Article uri icon

abstract

  • Epitaxial W/NbN superlattices with modulation wavelengths ranging from 1.3 to 25 nm were grown on MgO(001) substrates by dc reactive magnetron sputtering in Ar/N2 mixtures. The epitaxial relationship between the layers is given by W(001)NbN(001) and W[110]NbN[100]. X-ray diffraction and Rutherford backscattering results fitted using simulations showed that the superlattices had well-defined planar layers with interface widths of 0.2 nm. Nanoindentation measurements showed superlattice hardnesses as high as 33 GPa compared to 8 for W and 20 for NbN. The superlattices showed little change in x-ray superlattice reflections or nanoindentation hardness after vacuum annealing up to the highest temperature tested, 1000C for 6 h. Thus, the layers remained intact during annealing, allowing the superlattice hardness enhancement to be retained.

published proceedings

  • Journal of Vacuum Science & Technology A Vacuum Surfaces and Films

author list (cited authors)

  • Madan, A., Barnett, S. A., Misra, A., Kung, H., & Nastasi, M.

citation count

  • 35

complete list of authors

  • Madan, A||Barnett, SA||Misra, A||Kung, H||Nastasi, M

publication date

  • May 2001