Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states
We report heat capacity measurements of the pnictide materials SmFeAsO1−xFx , NdFeAsO, LaFeAsO1−xFx and LiFeAs. For SmFeAsO1−xFx ,with x close to 0.1, we use 3He measurements to demonstrate a transfer of entropy from the peak at TN to a previously unidentified ~ 2K feature, which grows with increasi...
| Main Authors: | , , , , , , , , , |
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| Other Authors: | |
| Format: | Journal article |
| Language: | English |
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Institute of Physics
2009
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| _version_ | 1797080535777935360 |
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| author | Baker, P Giblin, S Pratt, F Liu, R Wu, G Chen, X Pitcher, M Parker, D Clarke, S Blundell, S |
| author2 | Deutsche Physikalische Gesellschaft |
| author_facet | Deutsche Physikalische Gesellschaft Baker, P Giblin, S Pratt, F Liu, R Wu, G Chen, X Pitcher, M Parker, D Clarke, S Blundell, S |
| author_sort | Baker, P |
| collection | OXFORD |
| description | We report heat capacity measurements of the pnictide materials SmFeAsO1−xFx , NdFeAsO, LaFeAsO1−xFx and LiFeAs. For SmFeAsO1−xFx ,with x close to 0.1, we use 3He measurements to demonstrate a transfer of entropy from the peak at TN to a previously unidentified ~ 2K feature, which grows with increasing doping. Our results on the Sm samples are compared with a similarly doped La sample to elucidate the crystal field levels of the Sm3+ ion at 0, 20 and 45 meV, which lead to a Schottky-like anomaly, and also show that there is a significant increase in the Sommerfeld coefficient γ when La is replaced by Sm or Nd. The lattice contribution to the heat capacity of the superconducting oxypnictides is found to vary negligibly with chemical substitution. We also present a heat capacity measurement of LiFeAs showing the feature at Tc, which is significantly rounded and much smaller than the BCS value. |
| first_indexed | 2024-03-07T01:01:31Z |
| format | Journal article |
| id | oxford-uuid:89e54e85-c2f0-477e-af21-a96e423ea032 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:01:31Z |
| publishDate | 2009 |
| publisher | Institute of Physics |
| record_format | dspace |
| spelling | oxford-uuid:89e54e85-c2f0-477e-af21-a96e423ea0322022-03-26T22:27:42ZHeat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic statesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:89e54e85-c2f0-477e-af21-a96e423ea032PhysicsChemistry & allied sciencesInorganic chemistryEnglishOxford University Research Archive - ValetInstitute of Physics2009Baker, PGiblin, SPratt, FLiu, RWu, GChen, XPitcher, MParker, DClarke, SBlundell, SDeutsche Physikalische GesellschaftWe report heat capacity measurements of the pnictide materials SmFeAsO1−xFx , NdFeAsO, LaFeAsO1−xFx and LiFeAs. For SmFeAsO1−xFx ,with x close to 0.1, we use 3He measurements to demonstrate a transfer of entropy from the peak at TN to a previously unidentified ~ 2K feature, which grows with increasing doping. Our results on the Sm samples are compared with a similarly doped La sample to elucidate the crystal field levels of the Sm3+ ion at 0, 20 and 45 meV, which lead to a Schottky-like anomaly, and also show that there is a significant increase in the Sommerfeld coefficient γ when La is replaced by Sm or Nd. The lattice contribution to the heat capacity of the superconducting oxypnictides is found to vary negligibly with chemical substitution. We also present a heat capacity measurement of LiFeAs showing the feature at Tc, which is significantly rounded and much smaller than the BCS value. |
| spellingShingle | Physics Chemistry & allied sciences Inorganic chemistry Baker, P Giblin, S Pratt, F Liu, R Wu, G Chen, X Pitcher, M Parker, D Clarke, S Blundell, S Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title | Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title_full | Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title_fullStr | Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title_full_unstemmed | Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title_short | Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states |
| title_sort | heat capacity measurements on feas based compounds a thermodynamic probe of electronic and magnetic states |
| topic | Physics Chemistry & allied sciences Inorganic chemistry |
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