Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate
In order to unravel the magnetism of Co-doped ZnO films, we have performed rigorous experiments on Co-doped ZnO grown on O-polar ZnO (0001̄) substrates by molecular beam epitaxy. We find that the ZnO:Co with Co composition less than 20% is paramagnetic even at low temperatures, whereas that with Co...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2012
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| _version_ | 1797055695002009600 |
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| author | Li, L Guo, Y Cui, X Zheng, R Ohtani, K Kong, C Ceguerra, A Moody, M Ye, J Tan, H Jagadish, C Liu, H Stampfl, C Ohno, H Ringer, S Matsukura, F |
| author_facet | Li, L Guo, Y Cui, X Zheng, R Ohtani, K Kong, C Ceguerra, A Moody, M Ye, J Tan, H Jagadish, C Liu, H Stampfl, C Ohno, H Ringer, S Matsukura, F |
| author_sort | Li, L |
| collection | OXFORD |
| description | In order to unravel the magnetism of Co-doped ZnO films, we have performed rigorous experiments on Co-doped ZnO grown on O-polar ZnO (0001̄) substrates by molecular beam epitaxy. We find that the ZnO:Co with Co composition less than 20% is paramagnetic even at low temperatures, whereas that with Co composition of 20% shows ferromagnetism at room temperature. Although an additional n-type doping with Ga increases the magnitude of magnetization, the origin of the observed ferromagnetism is not carrier induced, as confirmed by electric-field effect measurements. Three-dimensional atom probe tomography shows that Co ions are randomly distributed, indicating that Co clustering or spinodal decomposition is not the origin of the ferromagnetism either. One possible mechanism for the ferromagnetism is hydrogen-facilitated interaction, which is supported experimentally by magnetic measurements on hydrogen-treated ZnO:Co as well as theoretically by first-principles calculation. © 2012 American Physical Society. |
| first_indexed | 2024-03-06T19:13:28Z |
| format | Journal article |
| id | oxford-uuid:178e43ca-286d-49d1-9289-a20c0cf4d492 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:13:28Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | oxford-uuid:178e43ca-286d-49d1-9289-a20c0cf4d4922022-03-26T10:38:04ZMagnetism of Co-doped ZnO epitaxially grown on a ZnO substrateJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:178e43ca-286d-49d1-9289-a20c0cf4d492EnglishSymplectic Elements at Oxford2012Li, LGuo, YCui, XZheng, ROhtani, KKong, CCeguerra, AMoody, MYe, JTan, HJagadish, CLiu, HStampfl, COhno, HRinger, SMatsukura, FIn order to unravel the magnetism of Co-doped ZnO films, we have performed rigorous experiments on Co-doped ZnO grown on O-polar ZnO (0001̄) substrates by molecular beam epitaxy. We find that the ZnO:Co with Co composition less than 20% is paramagnetic even at low temperatures, whereas that with Co composition of 20% shows ferromagnetism at room temperature. Although an additional n-type doping with Ga increases the magnitude of magnetization, the origin of the observed ferromagnetism is not carrier induced, as confirmed by electric-field effect measurements. Three-dimensional atom probe tomography shows that Co ions are randomly distributed, indicating that Co clustering or spinodal decomposition is not the origin of the ferromagnetism either. One possible mechanism for the ferromagnetism is hydrogen-facilitated interaction, which is supported experimentally by magnetic measurements on hydrogen-treated ZnO:Co as well as theoretically by first-principles calculation. © 2012 American Physical Society. |
| spellingShingle | Li, L Guo, Y Cui, X Zheng, R Ohtani, K Kong, C Ceguerra, A Moody, M Ye, J Tan, H Jagadish, C Liu, H Stampfl, C Ohno, H Ringer, S Matsukura, F Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title | Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title_full | Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title_fullStr | Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title_full_unstemmed | Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title_short | Magnetism of Co-doped ZnO epitaxially grown on a ZnO substrate |
| title_sort | magnetism of co doped zno epitaxially grown on a zno substrate |
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