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authors |
El Foulani, AH; Aamouche, A; Mohseni, F; Amaral, JS; Tobaldi, DM; Pullar, RC |
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nationality |
International |
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journal |
JOURNAL OF ALLOYS AND COMPOUNDS |
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author keywords |
Magnetism; Surfactant; Cobalt zinc ferrite; UV-Vis spectroscopy; Optical band gap |
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keywords |
CO1-XZNXFE2O4 NANOPARTICLES; SIZE; DEGRADATION; TEMPERATURE; EVOLUTION; REMOVAL |
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abstract |
Nanoparticles of zinc-cobalt spinel ferrite Co0.5Zn0.5Fe2O4 (CZFO) were prepared by co-precipitation route, and the effect of the addition of various surfactants (ethanol, PEG, CTAB and acetic acid; surfactant:metals = 0.5:1) on their magnetic and optical properties were investigated. Such surfactant additives have shown great potency in controlling and improving nucleation and growth stages, leading to an optimisation of crystallite size, porosity and specific surface area (SSA). The addition of ethanol in particular helped to optimise the physicochemical properties of the material, giving the lowest crystallite size of 11.7 nm, and highest porosity and SSA values of 0.65 cm(3)/g and 32.37 m(2)/g, respectively. The sample made with ethanol also had a small grain size of 50-100 nm. The CZFO made with ethanol surfactant also had greater coercivity (H-c) and saturation magnetisation (M-s) values compared with the other surfactants, of 22 kA m(-1) and 81.19 A m(2) kg(-1). UV-vis diffuse reflectance spectra (DRS) showed all samples made with surfactant additives had two distinct absorption edges in the visible region, around 550 nm and 700 nm. Two optical band gap (E-g) values were obtained for direct allowed transitions for these CZFO samples, with E-g1 values in the range of 1.99-2.06 eV, equivalent to that expected for ZnFe2O4, and E-g2 in the range of 1.60-1.66 eV, as expected for CoFe2O4. The CZFO made with ethanol also had the highest E-g values in both cases. (C) 2018 Elsevier B.V. All rights reserved. |
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publisher |
ELSEVIER SCIENCE SA |
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issn |
0925-8388 |
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isbn |
1873-4669 |
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year published |
2019 |
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volume |
774 |
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beginning page |
1250 |
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ending page |
1259 |
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digital object identifier (doi) |
10.1016/j.jallcom.2018.09.393 |
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web of science category |
Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering |
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subject category |
Chemistry; Materials Science; Metallurgy & Metallurgical Engineering |
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unique article identifier |
WOS:000449743600142
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