uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Initial Growth of BN on Diamond Substrates: A Theoretical Approach
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
2010 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, no 26, 11448-11455 p.Article in journal (Refereed) Published
Abstract [en]

Cubic boron nitride, c-BN, is a very interesting material due to its extreme properties of which some are comparable, or even superior, to diamond. Unfortunately, there are severe problems with the vapor phase synthesis of c-BN, which makes it very important to investigate the possibility for new growth pathways. The choice of substrate has been experimentally found to be decisive for an ideal growth of c-BN. Diamond is a material that has been found to be a good substrate for growth of c-BN directly onto the substrate. By using quantum mechanical density functional theory (DFT) under periodic boundary conditions, the details in the layer-by-layer formation of BN onto diamond (100) has been investigated in the present study. The prerequisites for an initial growth of c-BN (100) have been studied by adding the alternative B and N layers sequentially and calculating the resulting interfacial binding strengths and geometrical structures. For the situation with one monatomic layer on diamond, the interfacial binding energy was calculated to be strongest for nitrogen heteroepitaxially positioned onto diamond (100). The individual atoms in a monatomic B adlayer did, however, not choose corresponding heteroepitaxial positions. When applying a second atomic layer of c-BN, two different models were initially constructed with different structural alignments with respect to the underlying diamond structure. One model was heterostructurally positioned on top of diamond (100), while the other model had the x-axis of the c-BN lattice aligned with the y-axis of the diamond lattice. For the situation with N attached to the diamond substrate, the heteroepitaxial adlayer structure stayed cubic as a result of the geometry optimization, while the other became amorphous-like. Both of these adlayer structures showed large interfacial binding strengths, but the amorphous-like structure became energetically the most stable one. On the contrary, a two-layer BN structure with B attached to the diamond surface did not show the same characteristics. It was only the initial heteroepitaxial BN lattice that resulted in a stable adlayer structure. It stayed cubic after the geometry optimization, with a large interfacial binding strength. The four-layer BN structure on diamond showed similar features.

Place, publisher, year, edition, pages
2010. Vol. 114, no 26, 11448-11455 p.
National Category
Inorganic Chemistry
Research subject
Chemistry with specialization in Inorganic Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-136025DOI: 10.1021/jp911924gISI: 000279282200018OAI: oai:DiVA.org:uu-136025DiVA: diva2:376149
Available from: 2010-12-10 Created: 2010-12-09 Last updated: 2017-12-11Bibliographically approved
In thesis
1. The Effect of Boron in Metal Borides and BN – A Theoretical Approach
Open this publication in new window or tab >>The Effect of Boron in Metal Borides and BN – A Theoretical Approach
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Boron, B, has many interesting electronic and structural properties, which makes it an ideal material for technical and industrial needs. The different binary materials that have been in focus in the present thesis, do all include B; metal diborides (MB2), cubic boron nitride (c-BN) forming an interface with diamond, and various phases of BN [cubic (c-BN), hexagonal (h-BN), wurtzitic (w-BN), and rhombohedral (r-BN)]. Density Functional Theory (DFT) methods have been used in studying structural geometries, energetical stabilities, electronic properties, and surface reactivity.

A structural and electronic comparison has been made for various MB2 compounds in planar and puckered structural forms. The resulting MB2 structure was found to correlate to the degree of electron transfer from the metal atom to B. A transfer of more than one electron was observed to induce a planar B structure. This is to be compared with the planar MgB2 structure, for which an electron transfer of two electrons was observed.

The initial nucleation of c-BN onto a diamond substrate has also been focused in the present thesis. This step has experimentally been found to be critical for a phase-pure c-BN thin film growth to occur. The evolution of an interfacial diamond//BN structure was investigated, with the purpose to simulate a layer-by-layer growth of c-BN. The obtained results were found to strongly support the experimental findings, in that there is a need for an extra energy in order to avoid non-cubic phases in the closest vicinity to the substrate. However, the simulations showed that it is possible to diminish this need of extra energy by completely terminating the surface by species like H or F. These calculations also showed that terminated diamond//BN generally show a stronger interfacial bond energy, thereby improving the adhesion to the diamond substrate. The importance with surface termination was not found crucial for thicker BN adlayers.

A combined effect of doping and surface termination was investigated for the various BN allotropes, (using O, C, and Si). The electron induced in c-BN by the O (or C) dopant was observed to move towards the surface B atoms, and thereby creating a more reactive surface. For the upper surface N atoms, doping was observed to create a less reactive N surface. The Si dopants did only show a positive effect on surface reactivity at the B surface sites on both h-BN (001) and r-BN (001) surfaces.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2014. 87 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1124
National Category
Inorganic Chemistry
Research subject
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-218393 (URN)978-91-554-8879-6 (ISBN)
Public defence
2014-04-01, Häggsalen, Lägerhyddsvägen 1, Uppsala, 10:15 (English)
Opponent
Supervisors
Available from: 2014-03-10 Created: 2014-02-11 Last updated: 2014-04-29

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Pallas, AnnaLarsson, Karin

Search in DiVA

By author/editor
Pallas, AnnaLarsson, Karin
By organisation
Inorganic Chemistry
In the same journal
The Journal of Physical Chemistry C
Inorganic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 732 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf