New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects.
We provide a plausible resolution of a long-standing controversy relevant to the geophysics community, namely, that the experimental slope of the melting curve Tm(P) of MgO at low pressures is about 3 times smaller than that obtained from computer simulation of the melting of the normal rock-salt-st...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2005
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| _version_ | 1797050525821173760 |
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| author | Aguado, A Madden, P |
| author_facet | Aguado, A Madden, P |
| author_sort | Aguado, A |
| collection | OXFORD |
| description | We provide a plausible resolution of a long-standing controversy relevant to the geophysics community, namely, that the experimental slope of the melting curve Tm(P) of MgO at low pressures is about 3 times smaller than that obtained from computer simulation of the melting of the normal rock-salt-structured crystal. With increasing temperature at zero pressure, our simulations predict a solid-solid phase transition (from a rock salt to a wurtzite crystalline lattice) to occur just before melting. The coexistence of wurtzite and liquid phases at low pressures is found to be described by a Clapeyron slope which is in much better agreement with the experimental results of Zerr and Boehler [Nature (London) 371, 506 (1994)] than the calculated melting line for the rock salt structure. We also show that the existence of a certain concentration of lattice defects in the rock salt phase cannot provide an alternative explanation. |
| first_indexed | 2024-03-06T18:06:28Z |
| format | Journal article |
| id | oxford-uuid:0195d6ba-b008-4aed-9dd2-12ddd0d05ad5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T18:06:28Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:0195d6ba-b008-4aed-9dd2-12ddd0d05ad52022-03-26T08:35:52ZNew insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0195d6ba-b008-4aed-9dd2-12ddd0d05ad5EnglishSymplectic Elements at Oxford2005Aguado, AMadden, PWe provide a plausible resolution of a long-standing controversy relevant to the geophysics community, namely, that the experimental slope of the melting curve Tm(P) of MgO at low pressures is about 3 times smaller than that obtained from computer simulation of the melting of the normal rock-salt-structured crystal. With increasing temperature at zero pressure, our simulations predict a solid-solid phase transition (from a rock salt to a wurtzite crystalline lattice) to occur just before melting. The coexistence of wurtzite and liquid phases at low pressures is found to be described by a Clapeyron slope which is in much better agreement with the experimental results of Zerr and Boehler [Nature (London) 371, 506 (1994)] than the calculated melting line for the rock salt structure. We also show that the existence of a certain concentration of lattice defects in the rock salt phase cannot provide an alternative explanation. |
| spellingShingle | Aguado, A Madden, P New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title | New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title_full | New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title_fullStr | New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title_full_unstemmed | New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title_short | New insights into the melting behavior of MgO from molecular dynamics simulations: the importance of premelting effects. |
| title_sort | new insights into the melting behavior of mgo from molecular dynamics simulations the importance of premelting effects |
| work_keys_str_mv | AT aguadoa newinsightsintothemeltingbehaviorofmgofrommoleculardynamicssimulationstheimportanceofpremeltingeffects AT maddenp newinsightsintothemeltingbehaviorofmgofrommoleculardynamicssimulationstheimportanceofpremeltingeffects |