Riedel, Ralf ; Zerr, Andreas ; Miehe, Gerhard ; Serghiou, George ; Schwarz, Marcus ; Kroke, Edwin ; Fueß, Hartmut ; Kroll, Peter ; Boehler, Reinhard (1999)
Synthesis of cubic silicon nitride.
In: Nature, 400 (6742)
doi: 10.1038/22493
Article, Bibliographie
Abstract
Silicon nitride (Si3N4) is used in a variety of important technological applications. The high fracture toughness, hardness and wear resistance of Si3N4-based ceramics are exploited in cutting tools and anti-friction bearings1; in electronic applications, Si3N4 is used as an insulating, masking and passivating material2. Two polymorphs of silicon nitride are known, both of hexagonal structure: alpha- and beta-Si3N4. Here we report the synthesis of a third polymorph of silicon nitride, which has a cubic spinel structure. This new phase, c-Si3N4, is formed at pressures above 15 GPa and temperatures exceeding 2,000 K, yet persists metastably in air at ambient pressure to at least 700 K. First-principles calculations of the properties of this phase suggest that the hardness of c-Si3N4 should be comparable to that of the hardest known oxide (stishovite3, a high-pressure phase of SiO2), and significantly greater than the hardness of the two hexagonal polymorphs.
| Item Type: | Article |
|---|---|
| Erschienen: | 1999 |
| Creators: | Riedel, Ralf ; Zerr, Andreas ; Miehe, Gerhard ; Serghiou, George ; Schwarz, Marcus ; Kroke, Edwin ; Fueß, Hartmut ; Kroll, Peter ; Boehler, Reinhard |
| Type of entry: | Bibliographie |
| Title: | Synthesis of cubic silicon nitride |
| Language: | English |
| Date: | 22 July 1999 |
| Publisher: | NPG |
| Journal or Publication Title: | Nature |
| Volume of the journal: | 400 |
| Issue Number: | 6742 |
| DOI: | 10.1038/22493 |
| Abstract: | Silicon nitride (Si3N4) is used in a variety of important technological applications. The high fracture toughness, hardness and wear resistance of Si3N4-based ceramics are exploited in cutting tools and anti-friction bearings1; in electronic applications, Si3N4 is used as an insulating, masking and passivating material2. Two polymorphs of silicon nitride are known, both of hexagonal structure: alpha- and beta-Si3N4. Here we report the synthesis of a third polymorph of silicon nitride, which has a cubic spinel structure. This new phase, c-Si3N4, is formed at pressures above 15 GPa and temperatures exceeding 2,000 K, yet persists metastably in air at ambient pressure to at least 700 K. First-principles calculations of the properties of this phase suggest that the hardness of c-Si3N4 should be comparable to that of the hardest known oxide (stishovite3, a high-pressure phase of SiO2), and significantly greater than the hardness of the two hexagonal polymorphs. |
| Divisions: | 11 Department of Materials and Earth Sciences 11 Department of Materials and Earth Sciences > Material Science 11 Department of Materials and Earth Sciences > Material Science > Dispersive Solids 11 Department of Materials and Earth Sciences > Material Science > Structure Research |
| Date Deposited: | 08 Jun 2012 06:57 |
| Last Modified: | 26 Aug 2018 21:27 |
| PPN: | |
| Funders: | This work was supported by the Deutsche Forschungsgemeinschaft, Bonn, Germany, and the Fonds der Chemischen Industrie, Frankfurt, Germany. |
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