Ramakanth Illa; Jaroslav Hamrle; Jaromir Pištora
Abstract
Nanostructured thin films of MnFe2O4 were fabricated using chemical approach. Structural, magnetic, optical and magneto-optical properties of the films have been investigated using XRD, AFM, VSM, spectroscopic ellipsometry and MOKE spectroscopy. Structural evaluation of the thermally annealed films showed ...
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Nanostructured thin films of MnFe2O4 were fabricated using chemical approach. Structural, magnetic, optical and magneto-optical properties of the films have been investigated using XRD, AFM, VSM, spectroscopic ellipsometry and MOKE spectroscopy. Structural evaluation of the thermally annealed films showed crystalline phase and spinel structure along with appearance of textured nano-crystallites at the annealing temperature (Ta) of 500 °C and above. Surface morphology of the films annealed at 600 oC was characterized using AFM and the size of MnFe2O4 particles was observed to be 70 – 180 nm with ellipsoidal morphology and the surface roughness was found to be 8 nm. Hysteresis loops of the ferrite films indicated ferromagnetic behavior for annealing temperature of 400 oC and above, with a small contribution of paramagnetic nature arising from its oxide. The films showed a semiconducting behavior for the annealing temperature (Ta) ranging from 400 - 600 oC. The magneto-optical response is found to be small, i.e., one order less when compared to CoFe2O4 or metallic Fe, Co films. The maximum magneto-optical response from MnFe2O4 thin films is found for Ta = 400 oC, i.e. for incomplete spinel structure. As the material used for making the thin film coating is of the order of very few milligrams, these highly responsive films could be used as magnetic sensors. Copyright © 2017 VBRI Press.
Elangbam C. Devi; Ibetombi Soibam
Abstract
Manganese ferrite nanoparticles with chemical formula MnFe2O4 have been synthesized by low temperature chemical co-precipitation method. The structural and optical properties of the nanoparticles were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray ...
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Manganese ferrite nanoparticles with chemical formula MnFe2O4 have been synthesized by low temperature chemical co-precipitation method. The structural and optical properties of the nanoparticles were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), fourier transform infra-red spectroscopy (FTIR) and UV-visible absorption spectroscopy. XRD confirm pure spinel phase formation of the prepared sample. All the observed peaks correspond to the standard diffraction pattern of manganese ferrite having JCPDS card number 74-2403. From the XRD data, the average crystallite size was calculated and found to be 27.40 nm. The FTIR spectrum shows the characteristic bands of the spinel ferrite. Morphology of the nanoferrites was given by SEM image revealing that the particles are approximately spherical in shape. The elemental composition along with their relative ratios was given by EDAX and was found to be in agreement with their initial calculated values. UV- visible absorption spectrum of the prepared sample shows characteristic absorption in visible range and from the UV-visible absorption data the band gap of the prepared sample was determined. MnFe2O4 nanoparticles were found to possess a narrow band gap of 1.4 eV which may find applications in photocatalytic degradation of pollutants. The simple co-precipitation method proves to be an effective method for synthesis of pure phase manganese ferrite nanoparticles. Copyright © 2017 VBRI Press.
