The University of Southampton
University of Southampton Institutional Repository

Amorphous and nanocrystalline titanium nitride and carbonitride materials obtained by solution phase ammonolysis of Ti(NMe2)4

Amorphous and nanocrystalline titanium nitride and carbonitride materials obtained by solution phase ammonolysis of Ti(NMe2)4
Amorphous and nanocrystalline titanium nitride and carbonitride materials obtained by solution phase ammonolysis of Ti(NMe2)4
Solution phase reactions between tetrakisdimethylamidotitanium (Ti(NMe2)4) and ammonia yield precipitates with composition TiC0.5N1.1H2.3. Thermogravimetric analysis (TGA) indicates that decomposition of these precursor materials proceeds in two steps to yield rocksalt-structured TiN or Ti(C,N), depending upon the gas atmosphere. Heating to above 700 °C in NH3 yields nearly stoichiometric TiN. However, heating in N2 atmosphere leads to isostructural carbonitrides, approximately TiC0.2N0.8 in composition. The particle sizes of these materials range between 4–12 nm. Heating to a temperature that corresponds to the intermediate plateau in the TGA curve (450 °C) results in a black powder that is X-ray amorphous and is electrically conducting. The bulk chemical composition of this material is found to be TiC0.22N1.01H0.07, or Ti3(C0.17N0.78H0.05)3.96, close to Ti3(C,N)4. Previous workers have suggested that the intermediate compound was an amorphous form of Ti3N4. TEM investigation of the material indicates the presence of nanocrystalline regions <5 nm in dimension embedded in an amorphous matrix. Raman and IR reflectance data indicate some structural similarity with the rocksalt-structured TiN and Ti(C,N) phases, but with disorder and substantial vacancies or other defects. XAS indicates that the local structure of the amorphous solid is based on the rocksalt structure, but with a large proportion of vacancies on both the cation (Ti) and anion (C,N) sites. The first shell Ti coordination is approximately 4.5 and the second-shell coordination 5.5 compared with expected values of 6 and 12, respectively, for the ideal rocksalt structure. The material is thus approximately 50% less dense than known Tix(C,N)y crystalline phases.
titanium nitride, Ti3N4, amorphous, nanocrystalline, X-ray absorption spectroscopy, TEM, Raman scattering
0022-4596
1383-1393
Jackson, Andrew W.
049d4dbf-e5c9-4b4a-b5ae-bd16cd1b923b
Shebanova, Olga
e6580f7d-d9f0-48b1-84b1-43a2d6e9699e
Hector, Andrew L.
f19a8f31-b37f-4474-b32a-b7cf05b9f0e5
McMillan, Paul F.
8bca9219-06e0-4621-bdae-ad059709a147
Jackson, Andrew W.
049d4dbf-e5c9-4b4a-b5ae-bd16cd1b923b
Shebanova, Olga
e6580f7d-d9f0-48b1-84b1-43a2d6e9699e
Hector, Andrew L.
f19a8f31-b37f-4474-b32a-b7cf05b9f0e5
McMillan, Paul F.
8bca9219-06e0-4621-bdae-ad059709a147

Jackson, Andrew W., Shebanova, Olga, Hector, Andrew L. and McMillan, Paul F. (2006) Amorphous and nanocrystalline titanium nitride and carbonitride materials obtained by solution phase ammonolysis of Ti(NMe2)4. Journal of Solid State Chemistry, 179, 1383-1393. (doi:10.1016/j.jssc.2006.01.067).

Record type: Article

Abstract

Solution phase reactions between tetrakisdimethylamidotitanium (Ti(NMe2)4) and ammonia yield precipitates with composition TiC0.5N1.1H2.3. Thermogravimetric analysis (TGA) indicates that decomposition of these precursor materials proceeds in two steps to yield rocksalt-structured TiN or Ti(C,N), depending upon the gas atmosphere. Heating to above 700 °C in NH3 yields nearly stoichiometric TiN. However, heating in N2 atmosphere leads to isostructural carbonitrides, approximately TiC0.2N0.8 in composition. The particle sizes of these materials range between 4–12 nm. Heating to a temperature that corresponds to the intermediate plateau in the TGA curve (450 °C) results in a black powder that is X-ray amorphous and is electrically conducting. The bulk chemical composition of this material is found to be TiC0.22N1.01H0.07, or Ti3(C0.17N0.78H0.05)3.96, close to Ti3(C,N)4. Previous workers have suggested that the intermediate compound was an amorphous form of Ti3N4. TEM investigation of the material indicates the presence of nanocrystalline regions <5 nm in dimension embedded in an amorphous matrix. Raman and IR reflectance data indicate some structural similarity with the rocksalt-structured TiN and Ti(C,N) phases, but with disorder and substantial vacancies or other defects. XAS indicates that the local structure of the amorphous solid is based on the rocksalt structure, but with a large proportion of vacancies on both the cation (Ti) and anion (C,N) sites. The first shell Ti coordination is approximately 4.5 and the second-shell coordination 5.5 compared with expected values of 6 and 12, respectively, for the ideal rocksalt structure. The material is thus approximately 50% less dense than known Tix(C,N)y crystalline phases.

Full text not available from this repository.

More information

Submitted date: 6 January 2006
Published date: 3 March 2006
Keywords: titanium nitride, Ti3N4, amorphous, nanocrystalline, X-ray absorption spectroscopy, TEM, Raman scattering

Identifiers

Local EPrints ID: 35515
URI: http://eprints.soton.ac.uk/id/eprint/35515
ISSN: 0022-4596
PURE UUID: 7654fe8e-4e8f-469b-b4f9-be4feb4f0664
ORCID for Andrew L. Hector: ORCID iD orcid.org/0000-0002-9964-2163

Catalogue record

Date deposited: 17 May 2006
Last modified: 10 Sep 2019 00:52

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×