Kroll, Peter ; Andrade, Miria ; Yan, Xuehua ; Ionescu, Emanuel ; Miehe, Gerhard ; Riedel, Ralf (2012)
Isotropic Negative Thermal Expansion in β-Si(NCN)2and Its Origin.
In: The Journal of Physical Chemistry C, 116 (1)
doi: 10.1021/jp2106583
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Ab initio molecular dynamic simulations and high-temperature synchrotron crystallography show that β-Si(NCN)2 exhibits isotropic negative thermal expansion from 500 to 1123 K over its entire temperature stability range. The experimental value of the linear expansion coefficient changes from α = −1.24 × 10–6 K–1 at 500 K to α = −1.93 × 10–6 K–1 at 1123 K. Examination of vibrational motions locate the effect to transverse vibrations of carbodiimide fragments bridging between Si atoms (Si–N═C═N–Si). A detailed atomistic analysis reveals that the roto-vibrational movements of the bridging NCN units resemble that of a centrifugal governor pulling together the crystal framework upon temperature increase.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2012 |
| Autor(en): | Kroll, Peter ; Andrade, Miria ; Yan, Xuehua ; Ionescu, Emanuel ; Miehe, Gerhard ; Riedel, Ralf |
| Art des Eintrags: | Bibliographie |
| Titel: | Isotropic Negative Thermal Expansion in β-Si(NCN)2and Its Origin |
| Sprache: | Englisch |
| Publikationsjahr: | 2012 |
| Verlag: | ACS |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | The Journal of Physical Chemistry C |
| Jahrgang/Volume einer Zeitschrift: | 116 |
| (Heft-)Nummer: | 1 |
| DOI: | 10.1021/jp2106583 |
| Kurzbeschreibung (Abstract): | Ab initio molecular dynamic simulations and high-temperature synchrotron crystallography show that β-Si(NCN)2 exhibits isotropic negative thermal expansion from 500 to 1123 K over its entire temperature stability range. The experimental value of the linear expansion coefficient changes from α = −1.24 × 10–6 K–1 at 500 K to α = −1.93 × 10–6 K–1 at 1123 K. Examination of vibrational motions locate the effect to transverse vibrations of carbodiimide fragments bridging between Si atoms (Si–N═C═N–Si). A detailed atomistic analysis reveals that the roto-vibrational movements of the bridging NCN units resemble that of a centrifugal governor pulling together the crystal framework upon temperature increase. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Disperse Feststoffe 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 04 Apr 2012 07:37 |
| Letzte Änderung: | 05 Mär 2013 10:00 |
| PPN: | |
| Sponsoren: | German Science Foundation under the Priority Program SPP 1236 “Strukturen und Eigenschaften von Kristallen bei extrem hohen Drücken und Temperaturen”, Fonds der Chemischen Industrie, P.K. is supported by the NSF (DMR-0907117) and by the U.S. AFOSR and NASA under the National Hypersonics Science Center for Materials and Structures (AFOSR Contract No. FA9550-09-1-0477), The computational work was made possible through generous grants by the Texas Advanced Computing Center in Austin, TACC, Texas, and by the High Performance Computing Center at UTA |
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