The liquid<−>amorphous transition and the high pressure phase diagram of carbon.
The phase diagram of carbon is mapped to high pressure using a computationally-tractable potential model. The use of a relatively simple (Tersoff-II) potential model allows a large range of phase space to be explored. The coexistence (melting) curve for the diamond crystal/liquid dyad is mapped dire...
| Main Authors: | , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2013
|
| _version_ | 1797097484451840000 |
|---|---|
| author | Robinson, DR Wilson, M |
| author_facet | Robinson, DR Wilson, M |
| author_sort | Robinson, DR |
| collection | OXFORD |
| description | The phase diagram of carbon is mapped to high pressure using a computationally-tractable potential model. The use of a relatively simple (Tersoff-II) potential model allows a large range of phase space to be explored. The coexistence (melting) curve for the diamond crystal/liquid dyad is mapped directly by modelling the solid/liquid interfaces. The melting curve is found to be re-entrant and belongs to a conformal class of diamond/liquid coexistence curves. On supercooling the liquid a phase transition to a tetrahedral amorphous form (ta-C) is observed. The liquid <−> amorphous coexistence curve is mapped onto the pT plane and is found to also be re-entrant. The entropy changes for both melting and the amorphous −> liquid transitions are obtained from the respective coexistence curves and the associated changes in molar volume. The structural change on amorphization is analysed at different points on the coexistence curve including for transitions that are both isochoric and isocoordinate (no change in nearest-neighbour coordination number). The conformal nature of the melting curve is highlighted with respect to the known behaviour of Si. The relationship of the observed liquid/amorphous coexistence curve to the Si low- and high-density amorphous (LDA/HDA) transition is discussed. |
| first_indexed | 2024-03-07T04:56:11Z |
| format | Journal article |
| id | oxford-uuid:d6adcad6-94bb-4dad-b67c-64218c91b8b5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:56:11Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | oxford-uuid:d6adcad6-94bb-4dad-b67c-64218c91b8b52022-03-27T08:35:18ZThe liquid<−>amorphous transition and the high pressure phase diagram of carbon.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:d6adcad6-94bb-4dad-b67c-64218c91b8b5EnglishSymplectic Elements at Oxford2013Robinson, DRWilson, MThe phase diagram of carbon is mapped to high pressure using a computationally-tractable potential model. The use of a relatively simple (Tersoff-II) potential model allows a large range of phase space to be explored. The coexistence (melting) curve for the diamond crystal/liquid dyad is mapped directly by modelling the solid/liquid interfaces. The melting curve is found to be re-entrant and belongs to a conformal class of diamond/liquid coexistence curves. On supercooling the liquid a phase transition to a tetrahedral amorphous form (ta-C) is observed. The liquid <−> amorphous coexistence curve is mapped onto the pT plane and is found to also be re-entrant. The entropy changes for both melting and the amorphous −> liquid transitions are obtained from the respective coexistence curves and the associated changes in molar volume. The structural change on amorphization is analysed at different points on the coexistence curve including for transitions that are both isochoric and isocoordinate (no change in nearest-neighbour coordination number). The conformal nature of the melting curve is highlighted with respect to the known behaviour of Si. The relationship of the observed liquid/amorphous coexistence curve to the Si low- and high-density amorphous (LDA/HDA) transition is discussed. |
| spellingShingle | Robinson, DR Wilson, M The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title | The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title_full | The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title_fullStr | The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title_full_unstemmed | The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title_short | The liquid<−>amorphous transition and the high pressure phase diagram of carbon. |
| title_sort | liquid lt gt amorphous transition and the high pressure phase diagram of carbon |
| work_keys_str_mv | AT robinsondr theliquidltgtamorphoustransitionandthehighpressurephasediagramofcarbon AT wilsonm theliquidltgtamorphoustransitionandthehighpressurephasediagramofcarbon AT robinsondr liquidltgtamorphoustransitionandthehighpressurephasediagramofcarbon AT wilsonm liquidltgtamorphoustransitionandthehighpressurephasediagramofcarbon |