TY - JOUR
T1 - Growth, structure, and microhardness of epitaxial TiN/NbN superlattices
AU - Shinn, M.
AU - Barnett, S. A.
N1 - Funding Information:
The authors gratefully acknowledge the financial support of the National Science Foundation, Grant No. DMR 8817418. We also appreciate the use of the facilities at the Swedish National Center for HREM at University of Lund, and the assistance of Dr. L. R. Wallenberg in carrying out the HREM studies.
PY - 1992/4/1
Y1 - 1992/4/1
N2 - Epitaxial TiN/NbN superlattices with wavelengths A ranging from 1.6 to 450 nm have been grown by reactive magnetron sputtering on MgO(100). Cross-sectional transmission electron microscopy (XTEM) studies showed well-defined superlattice layers. Voided low-angle boundaries, aligned perpendicular to the film plane, were also present. High-resolution images showed misfit dislocations for A — 9.4 nm, but not A = 4.6 nm. Up to ninth-order superlattice reflections were observed in diffraction, indicating that the interfaces were relatively sharp. Analysis of the first-order x-ray superlattice reflection intensities indicated that the composition modulation amplitude increased and the coherency strains decreased for A increased from 2 to 10 nm. Vickers microhardness H was found to increase rapidly with increasing A, from 1700 kg/mm2for a TiN-NbN alloy (i.e., A = 0) to a maximum of 4900 kg/mm2at A = 4.6 nm. H decreased gradually for further increases in A above 4.6 nm, to H =2500 kg/mm2at A = 450 nm. The hardness results are compared with theories for strengthening of multilayers.
AB - Epitaxial TiN/NbN superlattices with wavelengths A ranging from 1.6 to 450 nm have been grown by reactive magnetron sputtering on MgO(100). Cross-sectional transmission electron microscopy (XTEM) studies showed well-defined superlattice layers. Voided low-angle boundaries, aligned perpendicular to the film plane, were also present. High-resolution images showed misfit dislocations for A — 9.4 nm, but not A = 4.6 nm. Up to ninth-order superlattice reflections were observed in diffraction, indicating that the interfaces were relatively sharp. Analysis of the first-order x-ray superlattice reflection intensities indicated that the composition modulation amplitude increased and the coherency strains decreased for A increased from 2 to 10 nm. Vickers microhardness H was found to increase rapidly with increasing A, from 1700 kg/mm2for a TiN-NbN alloy (i.e., A = 0) to a maximum of 4900 kg/mm2at A = 4.6 nm. H decreased gradually for further increases in A above 4.6 nm, to H =2500 kg/mm2at A = 450 nm. The hardness results are compared with theories for strengthening of multilayers.
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U2 - 10.1557/JMR.1992.0901
DO - 10.1557/JMR.1992.0901
M3 - Article
AN - SCOPUS:0026852996
SN - 0884-2914
VL - 7
SP - 901
EP - 911
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 4
ER -