Crystal structure and magnetic properties study on barium hexaferrite of different average crystallite size

Zinc oxide nanoparticles codoped with Co2+ and Mn2+ ions (Zn(1−x−y)MnxCoyO NPs) were obtained for the first time by microwave solvothermal synthesis. The nominal content of Co2+ and Mn2+ in Zn(1−x−y)MnxCoyO NPs was x = y = 0, 1, 5, 10 and 15 mol % (the amount of both ions was equal). The precursors were obtained by dissolving zinc acetate dihydrate, manganese (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate in ethylene glycol. The morphology, phase purity, lattice parameters, dopants content, skeleton density, specific surface area, average particle size, average crystallite size, crystallite size distribution and magnetic properties of NPs were determined. The real content of dopants was up to 25.0% for Mn2+ and 80.5% for Co2+ of the nominal content. The colour of the samples changed from white to dark olive green in line with the increasing doping level. Uniform spherical NPs with wurtzite structure were obtained. The average size of NPs decreased from 29 nm to 21 nm in line with the increase in the dopant content. Brillouin type paramagnetism and an antiferromagnetic interaction between the magnetic ions was found for all samples, except for that with 15 mol % doping level, where a small ferromagnetic contribution was found. A review of the preparation methods of Co2+ and Mn2+ codoped ZnO is presented.

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Nano-Crystalline Barium Hexaferrite Powders Prepared by Mechanical Alloying Using Acetate Precursor

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.610 ◽

2008 ◽

Vol 368-372 ◽

pp. 610-612 ◽

Cited By ~ 3

Author(s):

M. Honarvar Nazari ◽

Abolghasem Ataie ◽

S.A. Seyyed Ebrahimi

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Phase Composition ◽

Mechanical Alloying ◽

Thermal Behavior ◽

Crystallite Size ◽

Barium Hexaferrite ◽

Subsequent Heat Treatment ◽

Molar Ratios ◽

Nano Crystalline

Nano-crystalline barium hexaferrite powders have been prepared by mechanical alloying of nFe2O3+Ba(CH3COO)2 with Fe/Ba molar ratios of 10-12 and subsequent heat treatment. Thermal behavior, phase composition, morphology and magnetic properties of samples were studied using DTA/TGA, XRD, SEM and VSM, respectively. Nano-crystalline Ba-hexaferrite with a mean crystallite size of 46 nm and magnetic properties as high as Ms = 73.9 A.m2/kg and Hci = 334.2 kA/m was formed for mixture of 5.5Fe2O3+Ba(CH3COO)2 which was milled for 48 h and then annealed at 1100 °C.

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Magnetic Properties of the La0.50Ba0.50MnO3 Nanomanganites

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.152-153.135 ◽

2009 ◽

Vol 152-153 ◽

pp. 135-138 ◽

Cited By ~ 3

Author(s):

S.V. Trukhanov ◽

A.V. Trukhanov ◽

Christian E. Botez ◽

H. Szymczak

Keyword(s):

Magnetic Properties ◽

Crystallite Size ◽

Sol Gel ◽

Exchange Interactions ◽

Average Crystallite Size ◽

Anomalous Behavior ◽

Air Atmosphere ◽

Crystallite Surface ◽

Step Heat Treatment ◽

Lattice Compression

Nanocrystalline La0.50Ba0.50MnO3 manganite was synthesized by an optimized sol-gel method. The initial sample was subjected to step-by-step heat treatment under air atmosphere. The ion stoichiometry, the morphology of crystallites of ceramics, and the magnetic properties were studied. It is established that the average crystallite size increases with increasing annealing temperature. All of the samples studied are characterized by a perovskite-like cubic structure, with the unit cell parameter a increasing continuously with the average crystallite size. The most significant lattice compression occurs in the sample with an average crystallite size of ~ 30 nm. The increase in the average crystallite size causes a nonmonotonic increase in the Curie temperature and in the spontaneous magnetic moment. The anomalous behavior of the magnetic properties of the La0.50Ba0.50MnO3 manganites obtained is explained by the competition between two size effects, namely, the frustration of the indirect exchange interactions Mn3+ – O – Mn4+ on the nanocrystallite surface and the crystal lattice compression due to the crystallite surface tension.

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Structure and Magnetic Properties of Co-Substituted Strontium Hexaferrite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.979.200 ◽

2014 ◽

Vol 979 ◽

pp. 200-203 ◽

Cited By ~ 1

Author(s):

Pannipa Chaya ◽

Tula Jutarosaga ◽

Wandee Onreabroy

Keyword(s):

Crystal Structure ◽

Magnetic Properties ◽

Coercive Force ◽

Crystallite Size ◽

Strontium Hexaferrite ◽

X Ray Diffraction ◽

Ceramic Method ◽

Lattice Constants ◽

Structure Morphology ◽

Soft Ferrite

The strontium hexaferrite (SrFe12O19) and Co-substituted strontium hexaferrite (SrCoFe11O19) were prepared by ceramic method. The milled mixture of Fe2O3, SrCO3 and CoO powders were calcined at 1100°C and pellets sintered at 1300°C in air. The crystal structure, morphology and magnetic properties of samples have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM), respectively. The crystal structure of SrFe12O19 was hexaferrite with the crystallite size and the lattice constants a and c of 59.6 nm, 5.8 Å, and 23.0 Å, respectively. Also, the crystal structure of SrCoFe11O19 was hexaferrite with the crystallite size and the lattice constants a and c of 63.7 nm, 5.9 Å and 23.0 Å, respectively. The morphology of obtained samples changed from hexagonal rods to discs shape and grain sizes increased with the increase of doped Co in SrFe12O19. SrFe12O19 with the coercive force (Hc) of 2,133 Oe was classified as hard ferrite magnetic. While, Co-substituted strontium hexaferrite (SrCoFe11O19) was soft ferrite magnetic with coercive force of 64 Oe. Results indicated that magnetic properties of samples such as hard ferrite magnetic and soft ferrite magnetic showed great dependence on the cobalt additive in strontium.

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Crystal structure and magnetic properties of Cr doped barium hexaferrite

10.1063/1.5029110 ◽

2018 ◽

Author(s):

Sunil Kumar ◽

Sweety Supriya ◽

Rabichandra Pandey ◽

Lagen Kumar Pradhan ◽

Manoranjan Kar

Keyword(s):

Crystal Structure ◽

Magnetic Properties ◽

Barium Hexaferrite

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Crystal Structure of TiO2 Nanotube Arrays Anodized at Different Voltage for Cell-Metal Interaction

Materials Science Forum ◽

10.4028/www.scientific.net/msf.888.262 ◽

2017 ◽

Vol 888 ◽

pp. 262-266 ◽

Cited By ~ 2

Author(s):

Roshasnorlyza Hazan ◽

Srimala Sreekantan ◽

Ishak Mat

Keyword(s):

Crystal Structure ◽

Crystallite Size ◽

Anatase Phase ◽

Average Crystallite Size ◽

Cell Interaction ◽

Nanotube Arrays ◽

Direct Control ◽

Applied Potential ◽

Cell Behaviors ◽

Vertically Aligned

In recent study, vertically aligned TiO2 nanotubes have become the primary candidates that can provide direct control of many type cell behaviors and its functionality. TiO2 nanotubes were successfully developed within 10 V to 40 V of applied potential. The intensity of peaks (101) increases with increasing voltage up to 40 V, indicating an improvement in degree of crystalinity. The average crystallite size of the samples anodized at 10 V is about 19.65 nm and increase to 30.88 nm at 40 V. PA6 cell interaction were high on 40 V sample (110 nm-diameter) TiO2 nanotubes . It was found that anatase phase with appropriate diameter are believed to affect the growth of cells.

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Determination of the crystallite size and crystal structure of magnesium powder by x-ray diffraction

Jurnal Natural ◽

10.24815/jn.v20i3.16584 ◽

2020 ◽

Vol 20 (3) ◽

pp. 61-65

Author(s):

ISMAIL ISMAIL ◽

RESI MULIANI ◽

ZULFALINA ZULFALINA ◽

SITI HAJAR SHEIKH MD FADZULLAH

Keyword(s):

Crystal Structure ◽

Crystallite Size ◽

Rietveld Method ◽

Average Crystallite Size ◽

Powder Sample ◽

X Ray Diffraction ◽

Magnesium Powder ◽

X Ray ◽

Lattice Constants ◽

Packed Structure

Magnesium powder has become an important material in the development of science and technology such as alloy and hydrogen storage. In this work, the chemical composition, crystallite size, and crystal structure of the magnesium powder sample have been studied by using x-ray fluorescent and x-ray diffraction. The x-ray diffraction data of the magnesium powder sample was analyzed by using the Rietveld method to obtain the crystal structure. Our results show that the purity of our magnesium powder sample is 93.1%. Our sample has good crystallinity with the average crystallite size of 31 nm. The crystal structure is found to be a hexagonal closed-packed structure with the lattice constants of 3.2100 Å (a and b-axis) and 5.2107 Å (c-axis). Our result revealed that the lattice constant in the c-axis of magnesium powder is influenced by impurity. This finding suggests that the impurity can affect the crystal structure of a material in general.

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Microstructural and Magnetic Properties of Ti2+-Mn4+ Substituted Barium Hexaferrite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.896.401 ◽

2014 ◽

Vol 896 ◽

pp. 401-405 ◽

Cited By ~ 3

Author(s):

Maykel Manawan ◽

Azwar Manaf ◽

Bambang Soegijono ◽

Asep Yudi

Keyword(s):

Magnetic Properties ◽

Crystallite Size ◽

Single Phase ◽

Barium Hexaferrite ◽

X Ray Diffraction ◽

Mechanically Alloyed ◽

Microstructure Observation ◽

Diffraction Patterns ◽

Substituted Barium Hexaferrite ◽

Microstructure And Magnetic Properties

In this paper we report the microstructure and magnetic properties of Ti4+-Mn4+ ions substitued barium hexaferrites (BHF) with formula of BaFe12-2xMnxTixO19 (x = 0.2, 0.4, 0.6 and 0.8) which prepared by mechanical alloying and successive sintering at 1100 °C. Ti4+-Mn4+ ions were obtained from TiO2 and MnO precursors which were mechanically alloyed together with BaCO3 and Fe2O3 precursors. X-ray diffraction patterns for sintered samples confirmed that the materials are consisted with single phase BHF structure. Unit cell volume and crystallite size was found increase with increasing x. The crystallite size for all samples was below 70 nm, but microstructure observation shown that the particle size is in range of 200 - 400 nm, which concluded that the grains are polycrystalline. The saturation magnetization is increases up to x = 0.4 and decrease for higher x values, while the coercivity remain decreases monotonically. These results were interpreted in terms of the site preferential occupation of Ti2+ and Mn4+ at low level substitution.

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Magnetic and Catalytic Properties of Cu0.5Zn0.5Fe2O4 Nanocrystallite Powders

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2006.17914 ◽

2006 ◽

Vol 6 (1) ◽

pp. 114-119 ◽

Cited By ~ 12

Author(s):

M. M. Rashad ◽

M. H. Khedr ◽

K. S. Abdel-Halim

Keyword(s):

Magnetic Properties ◽

Crystallite Size ◽

Ferrous Sulfate ◽

Average Crystallite Size ◽

Sulfate Solution ◽

Stoichiometric Ratio ◽

Spent Catalyst ◽

Hydrothermal Temperature ◽

Iron And Steel ◽

Average Size

Cu0.5Zn0.5Fe2O4 nanocrystallite powders (average size 13 nm) were synthesized from Cu–Zn spent catalyst (fertilizers) industries and ferrous sulfate wastes formed during iron and steel making. Cu–Zn catalyst (22.4% Cu and 26.4% Zn) was chemically treated with sulfuric acid at temperature 80 °C for 1 hr for the complete dissolving of copper and zinc into sulfate solution, then the produced solution was mixed with stoichiometric ratio of ferrous sulfate and the mixture was chemically precipitated as hydroxides followed by hydrothermal processing. The parameters affecting the magnetic properties and crystallite size of the produced ferrites powder e.g., temperature, time, and pH were systemically studied. X-ray diffraction analysis was used in order to determine the average crystallite size and phase identifications of the produced powder. The magnetic properties were studied by vibrating sample magnetometry. The results showed that the average crystallite size of the powder decreased for the ferrites powder formed at 150 °C and then increased by increasing the temperature to 200 °C. Interestingly, the saturation magnetization (Bs), remanent magnetization (Br) and coercive force (Hc) were 25.03 emu/g, 0.71 emu/g, and 4.83 Oe, respectively at hydrothermal temperature 150 °C for 24 hr and changed to 16.38 emu/g, 0.3864 emu/g, and 5.2 Oe at 150 °C and 72 hr. The produced nanoferrite powders are used for studying the catalytic activity of CO conversion to CO2 at different temperatures, pH and times. The maximum conversion (82%) is obtained at temperature 150 °C for 24 hrs and pH 12.

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