Structural and Magnetic Properties of Mn Zn Ferrites (original) (raw)
Related papers
The European Physical Journal Applied Physics, 2008
In the present study, nano-ferrite of composition Mn0.4Zn0.6In0.5Al0.1Fe1.4O4 has been synthesized by co-precipitation method. Decomposition of residue at a temperature as low as 200 • C, gives the ferrite powder. The ferrite has been, finally, sintered at 500 • C. The structural studies have been made by using X-ray diffraction (XRD) technique and scanning electron microscopy (SEM), which confirms the formation of single spinel phase and nanostructure. The dc resistivity is studied as a function of temperature and values are found more than twice than those for the samples prepared by the other chemical methods ... It is found that the resistivity decreases with an increase in temperature. The initial permeability value is found to be higher as compared to the other chemical routes. The initial permeability value is found to increase with an increase in temperature. At a certain temperature called Curie temperature, it attains a maximum value, after which the initial permeability decreases sharply. Even at nanolevel, appreciable value of initial permeability is obtained and low magnetic losses make these ferrites especially suitable for high frequency applications. The particle size is calculated using Scherrer's equation for Lorentzian peak, which comes out between 55 nm-69 nm. Possible mechanisms contributing to these processes have been discussed.
Magnetic properties of nanostructured MnZn ferrite
Journal of Magnetism and Magnetic Materials, 2009
Mn 0.5 Zn 0.5 Fe 2 O 4 nanoparticles (10-30 nm) have been prepared via mechanochemical processing, using a mixture of two single-phase ferrites, MnFe 2 O 4 and ZnFe 2 O 4 . SQUID measurements (field-cooled magnetization curves and hysteresis loops) were performed to follow the mechanically induced evolution of the MnFe 2 O 4 /ZnFe 2 O 4 mixture submitted to the high-energy milling process. The resulting single MnZn nanoferrite phase was characterized by SQUID (M-H curve), Faraday balance (M-T curve) and transmission electron microscopy. The magnetic characteristics of the mechanosynthesized material were compared with those of bulk Mn 0.5 Zn 0.5 Fe 2 O 4 . It was found that the saturation magnetization of nanostructured Mn 0.5 Zn 0.5 Fe 2 O 4 (87.2 emu/g) is lower than that of the bulk Mn 0.5 Zn 0.5 Fe 2 O 4 , but, the Né el temperature of the sample (583 K) is higher than that of the bulk Mn 0.5 Zn 0.5 Fe 2 O 4 .
Investigation of frequency dependence permeability of Ca, Mg and Ti substituted Mn-Zn ferrites
2008
MnJ_xZnxFe204 (X=O, 0.2, 0.4, 0.5, 0.6), MnO.5ZnO.5_yCayF'e204 (y=OJ, 0.2), MnO.5ZnO.5_yMgyFe204 (y=OJ, 0.2) and MnO.5ZnO.5_yTiyF'e204 (y=O.l, 0.2) ferrites are prepared using conventional solid state reaction technique. The samples are sintered at two different temperatures (l200°C and 1300°C) in air for I hour. Structural and surface morphology are studied by x-ray diffraction (XRD) method and high resolution optical microscopy respectively. The magnetic properties of these ferrites are characterized by frequency (I kHz-13MHz) and temperature dependence complex permeability measurements. DC magnetizations (M) of all samples are measured using the Superconducting Quantum Interface Device (SQUID) magnetometer. The XRD patterns of all samples clearly indicate the formation of spinel structure. The change in lattice parameter can be explained on the basis of the ionic radii. The grain size increases with increasing Zn content in MnJ_xZnxFe204 as well as increase in density. Gr...
EFFECT OF PREPARATION ON MAGNETIC PROPERTIES OF Mn-Zn FERRITES
Indian Journal of Engineering and Materials Sciences (IJEMS) , 2004
Mixed ferrites belonging to the type Mn0.9Zn0.1Fe2O4 have been prepared by the double sintering method and by the chemical co-precipitation for comparing their magnetic properties. Sintered and precipitated ferrites exhibit different characteristics, especially in their magnetic properties like magnetization (Ms), coercive field (Hc) and Curie temperature (Tc). The sintered particles were size reduced in order to compare with the nanosized co-precipitated particles. The effect of grinding has also been studied. Particles have been collected at regular intervals of grinding and their properties have been studied. The increase in the coercive field has been recorded by a hysteresis curve tracer confirming size reduction. X-ray diffraction studies confirmed the structure and consequent size reduction.
Effect of preparation on magnetic properties of Mn-Zn ferrite
Mixed ferrites belonging to the type Mn 0.9 Zn 0.1 Fe 2 O 4 have been prepared by the double sintering method and by the chemical co-precipitation for comparing their magnetic properties. Sintered and precipitated ferrites exhibit different characteristics, especially in their magnetic properties like magnetization (M s), coercive field (H c) and Curie temperature (T c). The sintered particles were size reduced in order to compare with the nanosized co-precipitated particles. The effect of grinding has also been studied. Particles have been collected at regular intervals of grinding and their properties have been studied. The increase in the coercive field has been recorded by a hysteresis curve tracer confirming size reduction. X-ray diffraction studies confirmed the structure and consequent size reduction.
Indian Journal of Engineering Materials Sciences, 2008
Nano-ferrite of composition Mn 0.4 Zn 0.6 Al 0.1 Fe 1.9 O 4 synthesized by co-precipitation method has been reported. The structural studies have been made by using X-ray diffraction (XRD) technique and scanning electron microscopy (SEM), which confirms the formation of single spinel phase and nanostructure. The dc resistivity is studied as a function of temperature and values are found about two times more than those for the samples prepared by the other chemical methods due to stoichiometric composition and better crystal structure of the ferrite. Even at nanolevel, the value of initial permeability is found to be 495 and low magnetic losses make these ferrites especially suitable for high frequency applications. The particle size is calculated using Scherrer's equation for Lorentzian peak, which comes out between 32-43 nm. Possible mechanisms contributing to these processes have been discussed.
High density nanoparticle Mn-Zn ferrite synthesis, characterisation and magnetic properties
International Journal of Nanotechnology, 2011
The amazing magnetic properties exhibited by nanoparticles Mn-Zn ferrites and their promising technological and medical applications have attracted much interest in recent years. Nanoparticle Mn x Zn (1-x) Fe 2 O 4 spinel ferrites with x = 0.6/0.63/0.65/0.67/0.7 were synthesised by the nitrilotriacetate precursor method employing microwave combustion synthesis. Powder X-ray diffractometry (XRD) confirmed the formation of the ferrite phase in all samples. IR analysis was done to verify formation of spinel structure. Elemental analysis using EDS confirmed the nanoparticle composition. The crystallite size was calculated from peak widths using the Scherrer formula, yielding a size in the range of 10-25 nm. Transmission electron microscopy was also performed on the samples to testify formation of nanosized crystallites in the sample. Saturation magnetisation (Mr), retentivity (Ms) and coercivity (Hc) measurements were carried out on the samples using standard hysteresis
High Frequency Permeability of Mn-Zn Ferrite and its Composite Materials
Le Journal de Physique IV, 1997
Complex permeability spectra @*=p'-ip") in Mn-Zn ferrite and its composite materials have been studied. In sintered ferrite, resonance-type frequency dispersion was observed at room temperature but decrement ofp' is steeper than that of ordinary resonance. As the temperature is decreased, onset frequency of dispersion shifts higher and dispersion character changes to relaxation-type. In ferrite composite materials, relaxation characters were also observed at low volume loading samples. Since Kn-Zn ferrite has relatively high electrical conductivity at room temperature, high frequency permeability is suppressed by eddy current. However, lowering of temperature and reduction of ferrite content result in the decrease of eddy current; magnetic resonance such as relaxation-type spin rotational one appears in high frequency region.
Mn-Zn ferrite powders were produced from low-grade manganese ore (LMO) via the chemical coprecipitation method combined with the ceramic method, after the LMO was leached in sulfuric acid and the obtained solution was purified. The effect of the pH on the magnetic properties of Mn-Zn ferrite was investigated by the varying pH of the co-precipitation system. The crystal structure and phases of the samples were characterized by X-ray diffraction and infrared spectrum, respectively. The magnetic measurements were carried out on a vibrating sample magnetometer. The optimal sample was obtained with a saturation magnetization of 55.02 emu/g, a coercivity of 8.20 G and a remanent magnetization of 1.71 emu/g when pH is 7.5.