skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites

Abstract

Nanostructured materials such as nanocomposites and nanolaminates--subjects of intense interest in modern materials research--are defined by internal interfaces, the nature of which is generally unknown. Nevertheless, the interfaces often determine the bulk properties. An example of this is superhard nanocomposites with hardness approaching that of diamond. TiN/Si{sub 3}N{sub 4} nanocomposites (TiN nanocrystals encapsulated in a fully percolated SiN{sub x} tissue phase) and nanolaminates, in particular, have attracted much attention as model systems for the synthesis of such superhard materials. Here, we use in situ angle-resolved x-ray photoelectron spectroscopy to probe the electronic structure of Si{sub 3}N{sub 4}/TiN(001), Si/TiN(001), and Ti/TiN(001) bilayer interfaces, in which 4-ML-thick overlayers are grown in an ultrahigh vacuum system by reactive magnetron sputter deposition onto epitaxial TiN layers on MgO(001). The thickness of the Si{sub 3}N{sub 4}, Si, and Ti overlayers is chosen to be thin enough to insure sufficient electron transparency to probe the interfaces, while being close to values reported in typical nanocomposites and nanolaminates. The results show that these overlayer/TiN(001) interfaces have distinctly different bonding characteristics. Si{sub 3}N{sub 4} exhibits interface polarization through the formation of an interlayer, in which the N concentration is enhanced at higher substrate bias values during Si{sub 3}N{submore » 4} deposition. The increased number of Ti-N bonds at the interface, together with the resulting polarization, strengthens interfacial bonding. In contrast, overlayers of Si and, even more so, metallic Ti weaken the interface by minimizing the valence band energy difference between the two phases. A model is proposed that provides a semiquantitative explanation of the interfacial bond strength in nitrogen-saturated and nitrogen-deficient Ti-Si-N nanocomposites.« less

Authors:
 [1];  [2]; ; ;  [2]
  1. EMPA, Laboratory for Nanoscale Materials Science, Ueberlandstrasse 129 CH-8600 Duebendorf (Switzerland)
  2. Department of Materials Science and Frederick Seitz Materials Research Laboratory University of Illinois, 104 S. Goodwin Avenue, Urbana, Illinois 61801 (United States)
Publication Date:
OSTI Identifier:
21538196
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 83; Journal Issue: 12; Other Information: DOI: 10.1103/PhysRevB.83.125124; (c) 2011 American Institute of Physics; Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPOSITE MATERIALS; DEPOSITION; ELECTRONIC STRUCTURE; EPITAXY; HARDNESS; INTERFACES; LAYERS; MAGNESIUM OXIDES; MAGNETRONS; NANOSTRUCTURES; NITROGEN; POLARIZATION; SILICON NITRIDES; SIMULATION; SPUTTERING; SUBSTRATES; THICKNESS; TITANIUM NITRIDES; X-RAY PHOTOELECTRON SPECTROSCOPY; ALKALINE EARTH METAL COMPOUNDS; CHALCOGENIDES; CRYSTAL GROWTH METHODS; DIMENSIONS; ELECTRON SPECTROSCOPY; ELECTRON TUBES; ELECTRONIC EQUIPMENT; ELEMENTS; EQUIPMENT; MAGNESIUM COMPOUNDS; MATERIALS; MECHANICAL PROPERTIES; MICROWAVE EQUIPMENT; MICROWAVE TUBES; NITRIDES; NITROGEN COMPOUNDS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; PHOTOELECTRON SPECTROSCOPY; PNICTIDES; SILICON COMPOUNDS; SPECTROSCOPY; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS

Citation Formats

Patscheider, Joerg, Department of Materials Science and Frederick Seitz Materials Research Laboratory University of Illinois, 104 S. Goodwin Avenue, Urbana, Illinois 61801, Hellgren, Niklas, Messiah College, Department of Mathematical Sciences, P.O. Box 3041, One College Ave., Grantham, Pennsylvania 17027, Haasch, Richard T, Petrov, Ivan, and Greene, J E. Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites. United States: N. p., 2011. Web. doi:10.1103/PHYSREVB.83.125124.
Patscheider, Joerg, Department of Materials Science and Frederick Seitz Materials Research Laboratory University of Illinois, 104 S. Goodwin Avenue, Urbana, Illinois 61801, Hellgren, Niklas, Messiah College, Department of Mathematical Sciences, P.O. Box 3041, One College Ave., Grantham, Pennsylvania 17027, Haasch, Richard T, Petrov, Ivan, & Greene, J E. Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites. United States. https://doi.org/10.1103/PHYSREVB.83.125124
Patscheider, Joerg, Department of Materials Science and Frederick Seitz Materials Research Laboratory University of Illinois, 104 S. Goodwin Avenue, Urbana, Illinois 61801, Hellgren, Niklas, Messiah College, Department of Mathematical Sciences, P.O. Box 3041, One College Ave., Grantham, Pennsylvania 17027, Haasch, Richard T, Petrov, Ivan, and Greene, J E. Tue . "Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites". United States. https://doi.org/10.1103/PHYSREVB.83.125124.
@article{osti_21538196,
title = {Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites},
author = {Patscheider, Joerg and Department of Materials Science and Frederick Seitz Materials Research Laboratory University of Illinois, 104 S. Goodwin Avenue, Urbana, Illinois 61801 and Hellgren, Niklas and Messiah College, Department of Mathematical Sciences, P.O. Box 3041, One College Ave., Grantham, Pennsylvania 17027 and Haasch, Richard T and Petrov, Ivan and Greene, J E},
abstractNote = {Nanostructured materials such as nanocomposites and nanolaminates--subjects of intense interest in modern materials research--are defined by internal interfaces, the nature of which is generally unknown. Nevertheless, the interfaces often determine the bulk properties. An example of this is superhard nanocomposites with hardness approaching that of diamond. TiN/Si{sub 3}N{sub 4} nanocomposites (TiN nanocrystals encapsulated in a fully percolated SiN{sub x} tissue phase) and nanolaminates, in particular, have attracted much attention as model systems for the synthesis of such superhard materials. Here, we use in situ angle-resolved x-ray photoelectron spectroscopy to probe the electronic structure of Si{sub 3}N{sub 4}/TiN(001), Si/TiN(001), and Ti/TiN(001) bilayer interfaces, in which 4-ML-thick overlayers are grown in an ultrahigh vacuum system by reactive magnetron sputter deposition onto epitaxial TiN layers on MgO(001). The thickness of the Si{sub 3}N{sub 4}, Si, and Ti overlayers is chosen to be thin enough to insure sufficient electron transparency to probe the interfaces, while being close to values reported in typical nanocomposites and nanolaminates. The results show that these overlayer/TiN(001) interfaces have distinctly different bonding characteristics. Si{sub 3}N{sub 4} exhibits interface polarization through the formation of an interlayer, in which the N concentration is enhanced at higher substrate bias values during Si{sub 3}N{sub 4} deposition. The increased number of Ti-N bonds at the interface, together with the resulting polarization, strengthens interfacial bonding. In contrast, overlayers of Si and, even more so, metallic Ti weaken the interface by minimizing the valence band energy difference between the two phases. A model is proposed that provides a semiquantitative explanation of the interfacial bond strength in nitrogen-saturated and nitrogen-deficient Ti-Si-N nanocomposites.},
doi = {10.1103/PHYSREVB.83.125124},
url = {https://www.osti.gov/biblio/21538196}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 12,
volume = 83,
place = {United States},
year = {2011},
month = {3}
}