Structural, optical and magnetic properties of CoFe2O4 nanoparticle synthesized by ultrasonication-assisted sol–gel technique

Dubey, K. S.; Dubey, Shubha; Sahu, Vineet; Parry, Rayees Ahmed; Modi, Anchit

doi:10.1007/s00339-022-05681-z

Cited by 17 publications

(1 citation statement)

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“…These peaks are thought to be caused by charge transport between Co 2+ at tetrahedral sites and Fe 3+ at octahedral sites that are enclosed by O 2− ions [64]. It is possible to explain the fluctuation in the position and strength of absorption peaks by pointing out that gap surface disorders resulting from unsaturated bonds and surface non-stoichiometry are what cause the UV spectra to be The optical energy band gap (E g ) is estimated from absorption data with regard to the following formula [66]:…”

Section: Tem Analysismentioning

confidence: 99%

Influence of adding manganese chromium-layered double oxide on the optical, magnetic and dielectric properties of cobalt spinel ferrite nanoparticles

Rekaby,

Abou-Aly

2023

Phys. Scr.

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Hydrotalcite-like materials such as layered double oxides (LDOs) are promising materials for many technological applications. Linking the multilayer structure of LDOs with the exceptional optical, magnetic, and dielectric properties of spinel ferrites could result in advanced nanocomposites for photovoltaic, magneto-recording, and high-frequency applications. For that purpose, nanocomposites of type manganese chromium-layered double oxide/cobalt spinel ferrite, (MnCr)-LDOx/CoFe2O4 (x = 1, 3, and 5 wt%), were produced by the co-precipitation route. X-ray diffraction (XRD) analysis showed the successful incorporation of MnCr-LDO in CoFe2O4 lattice. After a 5 wt% addition of MnCr-LDO, the lattice parameter of pure CoFe2O4 increased from 8.3832 Å to 8.4136 Å, the crystallite size increased from 18.7 nm to 21.7 nm, and the strain dropped from 2.15 to 2.04. Transmission electron microscopy (TEM) revealed cubic morphologies for (MnCr)-LDOx/CoFe2O4 nanocomposites. Two strong absorbance peaks appeared in the Ultraviolet- visible (UV-vis) spectra (at ∼270 and ∼370 cm−1). The energy band gap and Urbach energy were estimated for the prepared samples. The composite sample (MnCr)-LDO1 wt%/CoFe2O4 recorded the highest band gap values (Eg1 = 3.39 eV, Eg2 = 4.46 eV, and Eg3 = 5.89 eV), while the (MnCr)-LDO3 wt%/CoFe2O4 sample had a relatively high Urbach energy value (1.35 eV). Vibrating sample magnetometer (VSM) analysis showed room temperature ferromagnetic (RTFM) behavior for the prepared composites. The saturation magnetization (Ms) value declined as the MnCr-LDO addition to CoFe2O4 increased, and the (MnCr)-LDO3 wt%/CoFe2O4 sample acquired the highest Ms (64.428 emu g−1) among all the produced composites. Pure CoFe2O4 had a much higher coercivity (Hc = 1158.1 Oe) than (MnCr)-LDOx/CoFe2O4 (x = 1, 3, and 5 wt%) nanocomposites (Hc = 1119.8, 978.48, and 984.16 Oe). Moreover, complex impedance spectroscopy measurements were performed in frequency range of 50 Hz- 5 MHz using Nyquist plots and electric modulus analysis. Nyquist plots were fitted to an analogous electric circuit consisting of a resistor R1 connected in series to two parallel constant phase element- resistor circuits (CPE-R). On the other hand, a different circuit comprises of two CPE, capacitor (C1), and resistor all connected in parallel was used to model CoFe2O4.

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Section: Tem Analysismentioning

confidence: 99%