Evidence of various stabilizing mechanisms in ferromagnetic Co doped ZnO nanocrystals
| Autor: | Swapnil Doke, Shailaja Mahamuni, Alok Banerjee, Kiran G. Sonawane |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Absorption spectroscopy Magnetism 02 engineering and technology 01 natural sciences law.invention Condensed Matter::Materials Science symbols.namesake Computer Science::Systems and Control law Condensed Matter::Superconductivity 0103 physical sciences Materials Chemistry 010306 general physics Electron paramagnetic resonance Condensed matter physics Mechanical Engineering Exchange interaction Doping Metals and Alloys 021001 nanoscience & nanotechnology Ferromagnetism Mechanics of Materials symbols Condensed Matter::Strongly Correlated Electrons Charge carrier 0210 nano-technology Raman spectroscopy |
| Zdroj: | Journal of Alloys and Compounds. 726:947-954 |
| ISSN: | 0925-8388 |
| Popis: | In spite of the extensive investigations on Co-doped ZnO, existence as well as origin of ferromagnetism remains controversial. Role of charge carriers and defects on the ferromagnetic ordering of Al, Co-codoped ZnO nanocrystals (NCs) having size as small as 5.5 nm is evaluated on the basis of optical spectroscopy, electron spin resonance and Raman spectroscopy. Al, Co-codoped ZnO NCs reveal improved saturation magnetization in a subtle way. Concomitant increase in the charge carriers is vivid from the optical absorption spectra of colloidal codoped NCs. The doping level is maintained low enough so that NCs are free of any secondary or impurity phase. Shape of the M(T) curves is analyzed to elucidate exchange interaction in doped ZnO NCs. The present experimental work indicates that the multiple mechanisms are responsible for stabilizing the ferromagnetic ordering in Co-doped ZnO NCs; thereby controversial reports are published in the literature. |
| Databáze: | OpenAIRE |
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