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Effect of High-Energy Ball Milling on the Magnetic ...

Abstract. High-density fine-grained Ni 0.5 Zn 0.5 Fe 2 O 4 ferrite ceramics were synthesized by spark plasma sintering (SPS) in conjunction with high energy ball milling. The precursor powders were milled for 20 h, 40 h, and 60 h, respectively, and the milled powders were all sintered for 5 min at 900 ° C. All the samples exhibit a single spinel phase.

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Comparison of the Characteristics of Nanocrystalline ...

talline ferrite by ball milling in Fe–0.89C steels with pearlite and spheroidite microstructures was compared in detail. The thermal stability of nanocrystalline ferrite was studied by an-nealing the ball-milled powders. Special attention was paid to find the influence of microstructure on the nanocrystallization process. 2. Experimental ...

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Mechanosynthesis of nanostructured magnetic Ni–Zn …

Nanocrystalline Ni–Zn ferrite (NiZnFe 2 O 4) was directly produced by high energy ball milling of stoichiometric mixture of ZnO, NiO, Fe 2 O 3 powders. The crystallite size of NiZnFe 2 O 4 after 60 h ball milling was estimated to be 18 nm which increased to 45 nm after annealing at 800 °C for 4 h.

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Structure and magnetic properties of nanocrystalline Ni Zn ...

0?5Fe 2O 4 ferrite powders also were investigate by Jalaly et al.11 and Ye et al.12 However, there are only a few reports on the characterisation of Ni–Zn ferrite powders synthesised by ball milling and structural evaluations and magnetic properties of ball milled prepared Ni 1-xZn xFe 2O 4 ferrite powders in some technologically important ...

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CN106747397A - YIG Ferrite Materials and preparation ...

YIG Ferrite Materials and preparation method, belong to Ferrite Material preparing technical field, and YIG Ferrite Materials of the invention include major ingredient and dopant, it is characterised in that major ingredient includes 47.8~61.1mol%Fe 2 O 3, 26.1~36.4mol%Y 2 O 3, 1.2~13.0mol%SnO 2, balance of CaCO 3 ；By weight percentage, calculated with oxide, …

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Microstructure characterization and cation distribution of ...

The XRD powder patterns from unmilled homogeneous mixture of MgO and α-Fe 2 O 3 and ball-milled samples are shown in Fig. 1.The powder pattern of the unmilled mixture shows the individual reflections of MgO and α-Fe 2 O 3 phases. MgO reflections are very weak (20.15 wt.%) when compared to those of α-Fe 2 O 3 (79.15 wt.%). As can be seen in the …

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CN105861978A - Mechanical ball milling method for ...

The invention relates to a mechanical ball milling method for producing iron nitride magnetic powder. The method using ball milling and nitriding includes: selecting iron powder 2-80 Mum in average particle size as a raw material, placing the iron powder into a ball milling tank, selecting a ball-material ratio to be 10:1-50:1, charging nitrogen 0.1-0.5 Mpa, or selecting ammonia …

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8-Influence of Particle Size on Microstructural

milling powder sizes were prepared through ball milling fo r various milling times to study the effect of powder size reduction on the resulting microstructural and magnetic properties. Sintered yttrium iron garnet ferrites were characterized by X-ray diffraction analysis and scanning electron microscopy. The particle size (D50) of

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Comparison of the Characteristics of Nanocrystalline ...

The nanocrystallization rate of pearlite powder is faster than that of spheroidite powder due to higher work-hardening rate and smaller cementite size. After long time ball milling, the equiaxed nanocrystalline ferrite with less than 10 nm grain size forms in the whole powders of both pearlite and spheroidite structures, and the cementite ...

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Structure of nanocrystalline MgFe - scripts.iucr

The three-dimensional structure of nanocrystalline magnesium ferrite, MgFe 2 O 4, prepared by ball milling, has been determined using synchrotron radiation powder diffraction and employing both Rietveld and atomic pair distribution function (PDF) analysis.The nanocrystalline ferrite exhibits a very limited structural coherence length and a high degree of structural disorder.

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Phase development during high-energy ball-milling of zinc ...

High-energy ball-milling of powder mixtures of zincite (ZnO) and iron (α-Fe) at different weight ratios was performed in air using a planetary ball mill with a stainless steel milling assembly. Structural and microstructural changes during the ball …

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Synthesis, Grain Growth, Cu-DOPING, and Magnetic ...

Abstract. Nanostructured powder of Ni-Zn ferrite was directly produced by high-energy ball milling of stoichiometric mixture of ZnO, NiO, and Fe 2 O 3 powders. X-ray powder diffractometry, scanning electron microscopy, annealing, treatment, and vibrating sample magnetometer were used to investigate the structural, chemical, and magnetic aspects of Ni …

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Effect of High-Energy Ball Milling on the Magnetic ...

High-density fine-grained Ni 0.5 Zn 0.5 Fe 2 O 4 ferrite ceramics were synthesized by spark plasma sintering (SPS) in conjunction with high energy ball milling. The precursor powders were milled for 20 h, 40 h, and 60 h, respectively, and the milled powders were all sintered for 5 min at 900˚C.

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Phase development during high-energy ball-milling of …

Structural and microstructural changes during the ball-milling (up to 30 h) were monitored using X-ray powder diffraction, field emission scanning electron microscopy (FE-SEM) and UV-Vis diffuse reflectance spectroscopy. The mechanism of iron oxidation was determined from the results of Möss spectroscopy.

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Magnetic properties and microstructure of Ba-ferrite ...

The magnetic properties and the phase constitution of barium ferrite powders with Fe/Ba ratios varying from 7 to 15 and heat-treated in the temperature range 1000–1200°C are reported.

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Research Article Effects of Milling Atmosphere and ...

Nanocrystalline Ni 0.36 Zn 0.64 Fe 2 O 4 was synthesized by milling a powder mixture of Zn, NiO, and Fe 2 O 3 in a high-energy ball mill for h under three di erent atmospheres of air, argon, and oxygen. A er sintering the h milled samples at C, the XRD patterns suggested the formation of a single phase of Ni-Zn ferrite.

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Mechanochemistry for ammonia synthesis under mild ...

The Fe(N*) powder were prepared by ball milling in N 2 (9 bar) at a rotation speed of 400 r.p.m. for 37.5 h. The ammonia was obtained by hydrogenating the as-prepared Fe(N*) at a rotation speed of ...

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Magnetic, optical, structural and thermal properties of ...

2O), and iron oxide (Fe 2O 3) are (79.97 μm, 99.78 %), (55 μm, 99.4 %) and (59.88 μm, 97.89 %) respectively. Cu, Cu 2O, and Fe 2O 4 powders were milled in ball milling machine (PM400) under controlled atmosphere with the tungsten car-bide balls. The ball/powder weight ratio is 1:20, and the time of milling varied from 0 to 20 h. 2.2 ...

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Magnetic properties of ball-milled SrFe12O19 particles ...

An increasing amount of Fe 3 O 4 is detected when the powder used for the consolidation has spent a longer time in the planetary ball mill. The presence of SrO is virtually impossible to detect in the X-ray diffractograms as all the SrO peaks overlap with the SrFe 12 O 19 and Fe 3 O 4 phases.

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Synthesis of austenitic stainless steel powder alloys by ...

The time for the formation of the austenite phase was shorter for the 12Ni and 13Ni powder blends than for the 8Ni powder. However, in the Fe–18Cr–15Ni and Fe–18Cr–20Ni compositions, the initial phase to form was ferrite and then a fully austenitic structure had formed on milling the powder for 10 h.

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Characterization of crystalline structure of ball-milled ...

ball mill (Model P5, M/s Fritsch, , Germany). In a planetary ball mill, a rotating disk carries vials that rotate in opposite direction. The rotation speed of the disk was 325rpm and that of the vials was about 475rpm. Milling of powder samples was done at room temperature in hardened chrome steel (Fe–1wt.% Cr) vial (volume 80ml) using 30

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Microstructure characterization and phase transformation ...

Analysis of ball-milled samples reveals that the inverse spinel phase content started to reduce in relatively long milling time and disappeared completely within 20 h milling time. After 25 h of milling, ball-milled powder mixture contain normal phase of Mg-Zn-ferrite with a …

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Effect of particle size of as-milled powders on ...

Yttrium iron garnet ferrite using the chosen stoichiometry of (Y 3)(Mn x Al 0.8-x Fe 4.2)O 12 with x = 0.1 and different milling powder sizes were prepared through ball milling for various milling times to study the effect of powder size reduction on …

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Thermal analysis, microstructure and impurity phases ...

12%to evidence the tendency for microstructure modification by impurities introduced during milling, the fe–14cr–3w–0.4ti–0.25y 2 o 3 (fe14cr) ferritic steel powders (re)loaded in air and milled up to 170 h with interruption of the milling process, and heated up to 1373 k were investigated by thermal analysis in correlation with x-ray diffraction …

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US Patent for Ferrite sintered magnet, motor and generator ...

A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in …

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US6210598B1 - Mn-Zn ferrite - Google Patents

A Mn—Zn ferrite having large electrical resistance, which can withstand use in high frequency region exceeding 1 MHz, is provided. The Mn—Zn ferrite comprises the following basic components: 44.0 to 50.0 mol % Fe 2 O 3, 4.0 to 26.5 mol % ZnO, 0.1 to 8.0 mol % at least one member selected from the group consisting of TiO 2 and SnO 2, and the remainder being MnO.

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Structure and magnetic properties of Ni0.64Zn0.36Fe2O4 ...

Nanocrystalline magnesium ferrite is synthesized by high-energy ball milling. The formation of nanocrystalline ferrite phase is observed after 3h of milling and its content increases with milling time. The structural and microstructural evolution of the nanophase have been studied by X-ray powder diffraction and the Rietveld method.

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Effect of High-Energy Ball Milling on the Magnetic ...

been limited reports on NiZn ferrite preparation by [9]. The aim of the present work is to fabricate a highSPS - density fine-grained Ni 0.5Zn 0.5Fe 2O 4 ferrite material by SPS in conjunction with high-energy ball millm-ing, e phasizing the effect of ball milling on the magnetic properties of resulting ceramics. 2. Experimental Procedure