Defect induced room temperature ferromagnetism and optical properties of (Co, Y) co-doped ZnO nanoparticles
| Autor: | N. Bhakta, P.K. Chakrabarti |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Photoluminescence Dopant Doping Hexagonal phase Analytical chemistry Infrared spectroscopy chemistry.chemical_element 02 engineering and technology Zinc 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Magnetization Ferromagnetism chemistry 0103 physical sciences 0210 nano-technology |
| Zdroj: | Journal of Magnetism and Magnetic Materials. 485:419-426 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/j.jmmm.2019.03.106 |
| Popis: | In this work, pristine zinc oxide (ZnO), Co2+ doped zinc oxide (ZCO) and Co-Y co-doped zinc oxides (ZCYO) are synthesized by sol-gel method. To increase the oxygen vacancy, the as-prepared samples are annealed in vacuum furnace. Refinement of the recorded X-ray diffractograms (XRD) shows that all the samples have grown in single hexagonal phase with space group P63mc and the nanocrystallites are grown with average sizes lie in the nanometer regime (10–29 nm). Fourier-transform infrared spectroscopy (FTIR) and photoluminescence (PL) spectroscopy could not detect any secondary phase except the desired one. Interestingly, room temperature ferromagnetism (RTFM) is observed in Co-Y co-doped sample where maximum magnetization is quite high (∼0.34 emu/g) compared with undoped ZnO. Absence of any metal cluster in ZCYO by XRD and optical analyses ruled out the ordering due to clustering. Thus origin of RTFM in ZCYO is intrinsic in nature. The defect mediated RTFM observed in ZCYO nanoparticles due to exchange interaction between dopants ions is explained by the oxygen vacancy together with the presence of the increase of surface defects due to co-doping of Co ion and non-magnetic Y ion. |
| Databáze: | OpenAIRE |
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