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Influence of Ni-dopant on the properties of synthetic goethite
| Content Provider | Semantic Scholar |
|---|---|
| Author | Krehula, Stjepko Svetozar Popović, Stanko |
| Copyright Year | 2005 |
| Abstract | The influence of Ni-dopand on the properties of alpha-FeOOH was investigated by XRD, FT-IR, 57Fe Mossbauer spectroscopy and transmission electron microscopy. alpha-FeOOH was synthesized at a highly alkaline pH by precipitation from the FeCl3 solution with the addition of tetramethylammonium hydroxide and autoclaving at 160 o ; C. The samples doped with Ni2+ ions were precipitated in the same way, but in the presence of varying concentrations of NiCl2. Solid solutions, having the structure of alpha-FeOOH, were observed in samples with the Ni/Fe ratio up to 0.05. Upon increasing the amount of Ni-dopand the XRD lines were gradually broadened. The sample with the ratio Ni/Fe = 0.10 showed NiFe2O4, besides the dominant phase having the structure type of alpha-FeOOH. Shifts of IR bands at 892 and 796 cm-1 were not observed in all samples doped with Ni. For the ratio Ni/Fe = 0.10, the IR bands centered at 631 and 404 cm-1 were significantly broadened. RT Mossbauer spectrum of undoped alpha-FeOOH and Ni-doped alpha-FeOOH showed distributions of hyperfine magnetic fields. Bhf decreased from 35.1 T for an undoped alpha-FeOOH to 32.1 T for alpha-FeOOH containing Ni2+ ions (Ni/Fe = 0.05). The saturation of the alpha-FeOOH structure with Ni2+ ions in amounts higher than ~ 5 mol % was also observed by Mossbauer spectroscopy. The particle size (length) of acicular alpha-FeOOH particles with a maximum in the interval 180-220 nm was slightly decreased with Ni-doping, but the distribution of the length/width ratio showed no change, having a maximum at 4 to 5. TEM photographs additionally showed small populations of cubic-shaped or pseudocubic particles of ~ 10 nm in size for the ratio Ni/Fe = 0.05 and about 10 to 20 nm in size for the ratio Ni/Fe = 0.10. These particles were assigned to NiFe2O4. |
| Starting Page | 368 |
| Ending Page | 375 |
| Page Count | 8 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.jallcom.2005.06.011 |
| Volume Number | 403 |
| Alternate Webpage(s) | https://bib.irb.hr/datoteka/213268.SKrehula-abstract-ICAME2005.pdf |
| Alternate Webpage(s) | https://doi.org/10.1016/j.jallcom.2005.06.011 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
