The Effect of Synthesis Temperature on Physical and Magnetic Properties of Manganese Ferrite (MnFe2O4) based on Natural Iron Sand (original) (raw)
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Journal of Physics: Conference Series, 2018
The magnetic material of Manganese Ferrite (MnFe2O4) based on natural Iron sand have been successfully prepared by using co-precipitation method. The natural Iron sand, MnCl2.4H2O, HCl and NH4OH were used as raw materials to synthesize the MnFe2O4. The synthesis was carried out at various temperatures of 70, 100 and 130°C, respectively. The physical and the magnetic properties of the samples were analysed by using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). The diffraction pattern indicates that the MnFe2O4 is the dominant phase. The crystallite size tends to increase as the synthesis temperature increased while the saturation magnetization of MnFe2O4 tends to decrease.
Preparation of nano-sized manganese ferrite (MnFe2O4) via coprecipitation method
physica status solidi (c), 2006
Nano-sized manganese ferrite (MnFe 2 O 4 ) powder has been synthesized via coprecipitation method, using FeSO 4 .7H 2 O and MnSO 4 .H 2 O as starting materials. An aqueous solution of the starting materials, containing Fe 2+ and Mn 2+ in the ratio required in the ferrite, was poured into an NaOH alkaline solution. A greenish precipitate was formed, which carefully washed and dried for 6 h at 80 °C. The dried powder was then heated for 2 h at different temperatures in argon atmosphere and then rapidly cooled to room temperature, using water quenching. XRD patterns of the samples show that the sample annealed at 1050 °C is single phase. Also using Scherrer's formula a mean crystallite size of 80 nm was obtained. Magnetic measurements were performed on cold pressed pellets, using a sensitive permeameter with a maximum field of 1.2 T. The results show that a single phase MnFe 2 O 4 nano-sized powder can be obtained at annealing temperature of 1050 °C, which is lower than 1250 °C related to the annealing temperature of the same ferrite, prepared by the conventional ceramic technique. Saturation magnetization of the single-phase sample was 1330 G, which is lower than 5000 G related to a bulk sample. The difference between the values is reasonable, because the magnetic measurements were performed on cold-pressed unsintered nano sized powders.
Reverse microemulsion process was employed to prepare of nanocrystalline Mn 3+ substituted MnFe2xMnxO4ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn 3+ . The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn 3+ . The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn 3+ in MnFe2O4ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn 3+ substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn3+ substitution was also analyzed. All the magnetic characterization shows that Mn 3+ substitution enhance the magnetic behavior of MnFe2O4ferrite nanoparticles.
International Journal of Nanoparticles, 2016
Nanoferrite powders having composition Mn x Mg 1-x Fe 2 O 4 (x = 0.0, 0.2, 0.4, 0.6, 0.8) were synthesised by the chemical co-precipitation method and then sintered as the pellets. The X-ray diffraction (XRD), Alternating Gradient Force Magnetometer (AGFM) techniques and Curie temperature measurement were used to carry out this study. The XRD patterns confirm the nanosized dimension of the samples and showed that the samples are single phase cubic spinel nanoferrites. From the analysis of XRD data using Scherrer's formula, the average crystallite size (D XRD) of the particles was found to decrease from 81 to 55 nm with increasing manganese substitution. Substitution of Mn 2+ in MgFe 2 O 4 causes an increase in the lattice constant (a) from 8.35 to 8.43 Å. The magnetic parameters such as saturation magnetisation (M S), coercivity (H C) and remanence (M r) with increasing Mn 2+ concentration are studied at room temperature by an AGFM. Substitution of Mn 2+ for Mg 2+ increased M S from 21.2 to 74.7 emu g-1 and decreased H C from 23 to 10 Oe and decreased Curie temperature from 392 to 294°C.
Journal of Physics: Conference Series, 2019
We have succeeded to synthesize the octahedral micro shape of MnFe2O4 through the co-precipation process followed by a ceramic processing method. At the beginning, the Mn3O4 and Fe2O3 nanoparticles were separately synthesized by the co-precipitation method from the low grade manganese ore and iron sand, respectively. Here, effect of the weight ratio of Fe2O3 and Mn3O4 to the crystal and microstructure of MnFe2O4 were investigated. Four cases of weight ratio i.e. 60:40, 70:30, 80:20, and 90:10 were considered. After mixing and compaction process in the cylindrical mould shape, the samples were sintered at 1000 o C and for 6 hours. XRD data showed that a high quality crystal phase of MnFe2O4 can be obtained for both mass ratio of 60:40 and 70:30, while in the case of 80:20 and 90:10 the MnFe2O4 appear together with impurity of D-Fe2O3. The particle shapes are almost octahedral in the micrometer size in the range of 1.2 to 1.5 m. The magnetic property shows a soft-magnetic type with a 27.5 emu/g of saturated magnetization. This will be potential for applications as the electrode materials and the magnetic core.
On the structure of manganese ferrite powder prepared by coprecipitation from MnO2 and FeSO4·7H2O
Materials Letters, 2000
The microstructure of manganese ferrite powder obtained from MnO and FeSO P 7H O by coprecipitation and aging in 2 4 2 Ž . isothermal static conditions at temperatures lower than 1008C, has been investigated by X-ray diffraction XRD , Mossbauer Ž . spectroscopy, granulometry and scanning electron microscopy SEM . The results reveal the influence of the temperature on the particle size distribution as well as on the structure and composition of the ferrite phase. Some magnetic properties of the ferrite powders are presented. q
Journal of Magnetism and Magnetic Materials, 2017
Nano-sized manganese ferrite (MnFe 2 O 4) particles were prepared using co-precipitation method in two different pH (9 and 11). The structural, morphological, optical and magnetic properties of as-synthesized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis absorption and vibrating sample magnetometer (VSM). The FTIR spectra revealed two strong peaks at about 600 and 400 ¹ that can be attributed to the vibration mode of octahedral and tetrahedral sites of spinel structure of MnFe 2 O 4 , respectively. The XRD results showed that the nanocrystalline MnFe 2 O 4 has pure cubic spinel crystal structure with average crystallite size of 11 nm. The cation distribution of these nanoparticles was estimated by x-ray analysis data. The blue shift was observed in the band gap when compared with bulk sample which is due to the quantum size effect. The absence of hysteresis for MnFe 2 O 4 nanoparticles indicated the superparamagnetic behaviour, as expected for single domain nanoparticles. The obtained value for saturation magnetization being less than its value of bulk ones and larger pH is due to surface effects. The calculated magnetic particle size was smaller than crystallite size estimated from the XRD results; which indicate the presence of dead layer on particle surface.
The effect of urea-to-nitrates ratio on the morphology and magnetic properties of Mn0.8Mg0.2Fe2O4
Journal of Magnetism and Magnetic Materials, 2010
Mn 0.8 Mg 0.2 Fe 2 O 4 ferrite was synthesized using flash auto-combustion technique using urea as fuel. The effect of the urea-to-nitrates ratio was examined and found to affect the samples characteristics. The asburnt powder was crystallized in single-phase spinel structure of cubic symmetry. The lattice parameter was decreased with increase in the urea-to-nitrates ratio (n) while the crystal size increased from 21 to 42 nm with n changing from 6.67 to 10. The coercivity increases while the saturation and remanence magnetization decreases with increase in n. This was attributed to the disturbance of the spin order as a result of the surface effects.
2021
Manganese ferrite spinel has been synthesized by using low grade manganese ore and ferric oxide as sources of manganese oxide and iron oxide through solid state reaction route by taking manganese and iron mole ratio of 1:2 respectively. The impact of sintering temperature on phase composition and particle size is investigated. Similarly, the impact of frequency on dielectric constant, dielectric loss, AC (alternating current) conductivity and tangent losses is also investigated. The results shows the presence of spinel structure manganese ferrite (MnFe2O4) as the major phase for the sample sintered at 1200 °C. It has been established that the crystallite size increase with rise in sintering temperature. The surface morphology of the sample sintered at 1200 °C show pyramidal and triangular shape grains. The dielectric constant (εʹ) and dielectric losses (εʹʹ) were observed to decrease with increasing the sintering temperature and frequency. Furthermore, the AC (alternating current) c...