scholarly journals Effects of Milling Atmosphere and Increasing Sintering Temperature on the Magnetic Properties of Nanocrystalline Ni0.36Zn0.64Fe2O4

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Abdollah Hajalilou ◽  
Mansor Hashim ◽  
Halimah Mohamed Kamari ◽  
Mohamad Taghi Masoudi
Keyword(s):  
Magnetic Properties ◽  
Sintering Temperature ◽  
Parallel Evolution ◽  
High Energy ◽  
High Energy Ball Mill ◽  
Zn Ferrite ◽  
Crystallite Sizes ◽  
Energy Ball ◽  
Xrd Patterns ◽  
Fesem Micrographs

Nanocrystalline Ni0.36Zn0.64Fe2O4was synthesized by milling a powder mixture of Zn, NiO, and Fe2O3in a high-energy ball mill for 30 h under three different atmospheres of air, argon, and oxygen. After sintering the 30 h milled samples at 500°C, the XRD patterns suggested the formation of a single phase of Ni-Zn ferrite. The XRD results indicated the average crystallite sizes to be 15, 14, and 16 nm, respectively, for the 30 h milled samples in air, argon, and oxygen atmospheres sintered at 500°C. From the FeSEM micrographs, the average grain sizes of the mentioned samples were 83, 75, and 105 nm, respectively, which grew to 284, 243, and 302 nm after sintering to 900°C. A density of all the samples increased while a porosity decreased by elevating sintering temperature. The parallel evolution of changes in magnetic properties, due to microstructural variations with changes in the milling atmosphere and sintering temperature in the rage of 500–900°C with 100°C increments, is also studied in this work.

scholarly journals Structural and Magnetic Properties of Ba3[Cu0.8−xZnxMn0.2]2Fe24O41 Z-Type Hexaferrites

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Eman S. Al-Hwaitat ◽  
Sami H. Mahmood ◽  
Mahmoud Al–Hussein ◽  
Ibrahim Bsoul
Keyword(s):  
Magnetic Properties ◽  
Anisotropy Field ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zn Content ◽  
Energy Ball ◽  
Structural And Magnetic Properties ◽  
Ball Milling Technique ◽  
Xrd Patterns

We report on the synthesis and characterization of Ba3[Cu0.8−xZnxMn0.2]2Fe24O41 (x = 0.0, 0.2, 0.4, 0.6, and 0.8) barium hexaferrites. The samples were prepared by high-energy ball-milling technique and double-sintering approach. The effects of Zn substitution for Cu on the structural and magnetic properties of the prepared samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). XRD patterns of the samples revealed the presence of a major Z-type hexaferrite phase, together with secondary M-type and Y-type phases. The magnetic results indicated that the saturation magnetization increased slightly with increasing the Zn content, while the coercivity and magnetocrystalline anisotropy field exhibited a decreasing tendency with the increase of Zn content. The thermomagnetic curves revealed the complex magnetic structure of the prepared samples and confirmed that the Curie temperature of the magnetic phases decreased with increasing x as a result of the reduction of the strength of the superexchange interactions.

A Study of Pb (Zr0.52Ti0.48)O3 Ceramic Properties via High Energy Ball Mill

2015 ◽  
Vol 1087 ◽  
pp. 223-226
Author(s):  
Shafiza Afzan Sharif ◽  
J.M. Juliewatty ◽  
W.A.W. Yusoff
Keyword(s):  
Perovskite Phase ◽  
High Energy ◽  
Soaking Time ◽  
Grain Sizes ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Higher Temperature ◽  
Ball Milling Technique ◽  
Xrd Patterns ◽  
The Relationship

Pb (Zr0.52Ti0.48)O3, (PZT) powder has been synthesized using high energy ball milling technique. The synthesized powders were characterized using XRD, SEM, Density, Porosity and Impedance Analyzer. XRD patterns show that the perovskite phase of PZT can be formed from the mixture of starting material after milling for 40 h. The grain sizes of the powder have been estimated to be 1-3 μm. The relationship between the microstructure of the PZT samples and sintering temperature has been discussed. Dense PZT (> 95 % theoretical density) with excellent dielectric properties was obtained when the pellet are sintered at higher temperature with shorter soaking time. The results show that the sample sintered at 1100 °C /1 h yields a clearly uniform grain size with the highest dielectric constant.

SYNTHESIS, GRAIN GROWTH, Cu-DOPING, AND MAGNETIC PROPERTIES OF NANOCRYSTALLINE Ni–Zn FERRITE

2010 ◽  
Vol 24 (09) ◽  
pp. 1067-1077 ◽  
Author(s):  
MAISAM JALALY ◽  
MOHAMMAD-HOSEIN ENAYATI ◽  
PARVIZ KAMELI ◽  
FATHOLLAH KARIMZADEH
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
Annealing Treatment ◽  
High Energy ◽  
Stoichiometric Mixture ◽  
Cu Doping ◽  
X Ray ◽  
Zn Ferrite ◽  
Energy Ball ◽  
Effect Of Copper

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 0.5 Zn 0.5 Fe 2 O 4 compound. The crystallite size of final product after 60 h of ball milling time was estimated to be 17 nm. Heat treatment of ball-milled Ni – Zn ferrite was performed to study the thermal behavior of ferrite. The effect of copper doping on structure and magnetic properties of Ni – Zn ferrite was also studied. The results showed that the Zn replacement with Cu led to a decrease of magnetization.

The Influence of the Sintering Temperature on the Wear Testing for Some Steels Samples Obtained by Powder Metallurgy

2014 ◽  
Vol 216 ◽  
pp. 216-221 ◽  
Author(s):  
Bebe Adrian Olei ◽  
Iulian Ştefan ◽  
Nicoleta Popescu
Keyword(s):  
Powder Metallurgy ◽  
Ball Mill ◽  
Sintering Temperature ◽  
Wear Behavior ◽  
High Energy ◽  
Wear Testing ◽  
Iron Powders ◽  
High Energy Ball Mill ◽  
Energy Ball

The objective of this research is to observe the influence of the sintering temperature on the wear testing for some steel samples elaborated by powder metallurgy technology. For obtaining the steels there were used iron powders and graphite powders. The powders were homogenized in a high energy ball mill Pulverisette 6, cold compacted and then sintered in a furnace. The sintering parameters are: the sintering temperature, T = (1050, 1100, 1150)°C and the maintaining time, t = 60 minutes. The influence of the sintering parameters on the samples wear behavior is studied using both a tribometer and a profilometer.

Magnetic Properties of Nanocrystalline Fe50Co50 Powders

2003 ◽  
Vol 788 ◽  
Author(s):  
Shashishekar Basavaraju ◽  
Ian Baker
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Magnetic Force ◽  
Milling Time ◽  
Magnetic Behavior ◽  
High Energy ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
High Energy Ball Mill ◽  
Energy Ball

ABSTRACTNanocrystalline stoichiometric FeCo powders were prepared by mechanically alloying elemental Fe and Co powders using a high-energy ball mill. The microstructural evolution was studied as a function of milling time and subsequent annealing using X-ray diffractometry and differential scanning calorimetry. The magnetic behavior of the specimens was characterized using a vibrating sample magnetometer and a magnetic force microscope. A reduction in grain size coupled with an increase in coercivity was observed as function of milling time. The smallest grain size of 4 nm, which exhibited a coercivity of 122 Oe and magnetization of 2 T at room temperature, was obtained after 240 h of milling. The reduction in grain size during milling was not accompanied by enhanced soft magnetic properties.

Structure and Magnetic Properties of Ternary Nanosized FeAlSn and CuFeCo Powders Synthesized by Mechanical Milling

2017 ◽  
Vol 47 ◽  
pp. 79-88 ◽  
Author(s):  
Z. Hamlati ◽  
W. Laslouni ◽  
Mohammed Azzaz ◽  
M. Zergoug ◽  
D. Martínez-Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Milling Time ◽  
Magnetic Measurements ◽  
High Energy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
High Energy Ball Mill ◽  
Powder Particles ◽  
Energy Ball

Ternary Fe72Al26Sn2 and Cu70Fe18Co12 alloys were obtained by mechanical alloying of pure Fe, Al, Sn, Cu and Co powders using a high energy ball mill. X-ray diffraction and electron microscopy supported by magnetic measurements have been applied to follow changes in the microstructure, phase composition and magnetic properties in dependence on milling time. With the increase of milling time all Al and Sn atoms dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe (Al, Sn) solid solution in a metastable state with a large amount of defects and mean crystallite size of 5 nm. However, the obtained crystallite size value is about 10 nm for the ball milled Cu70Fe18Co12 powders. The electron microscope observations show the morphology of powder particles. Magnetic properties of the nanocrystalline mechanically alloyed FeAlSn and CuFeCo were also investigated and were related to the microstructural changes.

scholarly journals Effect Of Heat-Treatment On Microstructure And Magnetic Properties Of Nanocrystallized Mn-Zn Ferrite Powders

2015 ◽  
Vol 60 (2) ◽  
pp. 1347-1350
Author(s):  
W.H. Lee ◽  
C.S. Hong ◽  
S.Y. Chang
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
High Energy ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Zn Ferrite ◽  
Energy Ball ◽  
Size Of Particles ◽  
Increasing Temperature

Abstract The initial ferrite powders were subjected to high energy ball milling at 300rpm for 3h, and subsequently heat-treated at 573-1273K for 1h. Based on the observation of microstructure and measurement of magnetic properties, the heat-treatment effect was investigated. The size of initial powders was approximately 70μm. After milling, the powders with approximately 230nm in size were obtained, which were composed of the nano-sized particles of approximately 15nm in size. The milled powders became larger to approximately 550nm after heat-treatment at 973K. In addition, the size of particles increased to approximately 120nm with increasing temperature up to 973K. The coercivity of initial powders was almost unchanged after milling, whereas the saturation magnetization increased. As the heat-treatment temperature increased, the saturation magnetization gradually increased and the maximum coercivity was obtained at 773K.

STRUCTURAL TRANSITION OF NANOCRYSTALLINE TiO2

2011 ◽  
Vol 10 (01n02) ◽  
pp. 59-63 ◽  
Author(s):  
MANORANJAN KAR ◽  
N. RAMA KRISHNAN ◽  
INDRAJIT TALUKDAR ◽  
K. ACHARYYA
Keyword(s):  
Crystallite Size ◽  
Bulk Material ◽  
Anatase Phase ◽  
Average Crystallite Size ◽  
Rutile Phase ◽  
High Energy ◽  
Nanocrystalline Tio2 ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Xrd Patterns

Nanocrystalline TiO 2 sample was prepared by high-energy ball mill method. A known quantity of anatase phase- TiO 2 was milled for 83 h in air. The samples were collected at intervals of 5 h of milling. The XRD patterns were recorded for all the samples. The crystal structure changed from anatase phase for bulk material to rutile-rich phase for nanocrystalline material. Nanocrystalline TiO 2, which is a mixture of anatase, rutile, and srilankite phase, was prepared by milling for 60 h. The XRD pattern of unmilled anatase phase of TiO 2 could be refined with I41/amd space group. The crystallite size of the TiO 2 was found to decrease with milling time upto 50 h and then the size of rutile phase increases while the sizes of anatase and srilankite phases remain constant upto 60 h of milling. After 60 h, the sizes of all the phases remain constant. The average crystallite size for rutile phase is found to be 12 nm after 60 h of milling.

scholarly journals Structural and Magnetic Properties of (Mg, Co)2W Hexaferrites

2020 ◽  
Vol 13 (1) ◽  
pp. 1-16
Keyword(s):  
Magnetic Properties ◽  
Sintering Temperature ◽  
High Energy ◽  
Spin Reorientation ◽  
Magnetic Data ◽  
Sem Images ◽  
Intermediate Phases ◽  
Structural And Magnetic Properties ◽  
Xrd Patterns ◽  
Precursor Powders

Precursor powders of BaMg2-xCoxFe16O27 with (x = 0.0, 1.0, and 2.0) were prepared using high-energy ball milling and the effects of chemical composition and sintering temperature on the structural and magnetic properties were investigated using x-ray diffractometer (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). XRD patterns of the prepared samples indicated that crystallization of pure BaW hexaferrite phase was achieved at a sintering temperature of 1300° C, while BaM and cubic spinel intermediate phases were obtained at lower sintering temperatures of 1100° C and 1200° C. SEM images revealed an improvement of crystallization of the structural phases and a growth of the particle size with increasing the sintering temperature. The magnetic data of the samples sintered at 1300° C revealed an increase of the saturation magnetization from 59.4 emu/g to 72.6 emu/g with increasing Co concentration (x) from 0.0 to 2.0. The coercive field Hc decreased from 0.07 kOe at x = 0.0 to 0.03 kOe at x = 1.0 and then increased to 0.09 kOe at x = 2.0. The thermomagnetic curves of the samples sintered at 1300° C confirmed the existence of the W-type phase and revealed spin reorientation transitions in Co-containing samples.

Sintering of Fe-TiC Composite Prepared by Carbothermal Reduction of Hematite and Anatase

2011 ◽  
Vol 471-472 ◽  
pp. 670-673
Author(s):  
Mohd Salihin Hassin ◽  
Palaniandy Samayamutthirian ◽  
Zuhailawati Hussain
Keyword(s):  
Carbothermal Reduction ◽  
Sintering Temperature ◽  
Milled Powder ◽  
High Energy ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Cold Pressed ◽  
And Diffusion

In this study, the formation of Fe-TiC composite through carbothermal reduction of hematite and anatase was investigated with various sintering temperature. Mixture of hematite and anatase powders was milled with graphite for 20 hours in a high energy ball mill in argon atmosphere with composition of Fe-30%volTiC. The as-milled powder was analyzed with X-ray diffraction analysis and the result shows broadening of hematite peaks with disappearance of anatase and graphite peaks due to refinement of powder and diffusion of carbon. The as-milled powder was cold pressed under 200 MPa and sintered in argon atmosphere at various sintering temperature i.e, 1200°C, 1300°C and 1400°C. Higher sintering temperature facilitated reduction of hematite and anatase to produce Fe-TiC composite.

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