Preparation and Magnetic Properties of Nanocrystal Bulk SmCo7 Magnets

2015 ◽  
Vol 815 ◽  
pp. 276-280 ◽  
Author(s):  
Qian Shen ◽  
Yi Long Ma ◽  
Jun Dong ◽  
Deng Ming Chen
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Ball Milling ◽  
Hot Pressing ◽  
Amorphous Powder ◽  
High Energy ◽  
High Coercivity ◽  
Energy Ball ◽  
Bulk Nanocrystalline ◽  
Co Alloys

Two kinds of 2:17R Sm-Co alloys, Sm2(Fe,Cu,Zr,Co)17 and pure binary Sm2Co17 were prepared, and the amorphous powder was prepared by high-energy ball milling Sm-Co alloys. The bulk nanocrystalline SmCo7 was prepared by hot-pressing the amorphous powder, and the magnetic properties and phase composition were studied. Initial Sm2(Fe,Cu,Zr,Co)17 showed a large value of coercivity while the pure Sm2Co17 almost showed no coercivity. However, after ball milling the grain size of alloys decreased dramatically until completely amorphous. Two kinds of alloys showed the different phase composition and magnetic properties after hot-pressing. It was found that the pure Sm2Co17 bulk magnet showed a high coercivity Hc and had the 1:7H phase. On the other hand, the Sm2(Fe,Cu,Zr,Co)17 showed high saturation magnetization Ms and very low Hc since the Fe-Co and Sm2Co3 phase were precipitated from the alloy.

Synthesis of Magnetic Nano-Composite by Partial Reduction of Barium Hexaferrite via High-Energy Ball Milling

2010 ◽  
Vol 434-435 ◽  
pp. 354-356 ◽  
Author(s):  
M.J. Molaei ◽  
Abolghasem Ataie ◽  
Sh. Raygan
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Ball Milling ◽  
Milling Time ◽  
Barium Hexaferrite ◽  
High Energy ◽  
Partial Reduction ◽  
Nano Composite ◽  
Energy Ball ◽  
Dominant Phase

In this work, nano-composite of barium hexaferrite/magnetite was produced by partial reduction of barium hexaferrite with graphite via ball milling. Phase composition, morphology and magnetic properties of the samples were evaluated by XRD, SEM and VSM, respectively. XRD results revealed that after 15 hours milling, a nano-composite of BaFe12O19/Fe3O4 formed which mean crystallite size of BaFe12O19 was 17 nm. After milling for 20 and 40 hours, the peaks of BaFe12O19 were weakened and Fe3O4 was detected as a dominant phase. The coercivity decreased from 703 to 153 Oe when the milling time increased from 15 to 20 hours.

scholarly journals Magnetic properties and crystal structure of elemental cobalt powder modified by high-energy ball milling

2019 ◽  
Vol 8 (5) ◽  
pp. 4995-5003 ◽  
Author(s):  
J.A. Betancourt-Cantera ◽  
F. Sánchez-De Jesús ◽  
A.M. Bolarín-Miró ◽  
G. Torres-Villaseñor ◽  
L.G. Betancourt-Cantera
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Cobalt Powder ◽  
Energy Ball

scholarly journals Magnetic properties of iron nitride-alumina nanocomposite materials prepared by high-energy ball milling

2003 ◽  
Vol 24 (1-3) ◽  
pp. 93-96 ◽  
Author(s):  
S. R. Mishra ◽  
G. J. Long ◽  
F. Grandjean ◽  
R. P. Hermann ◽  
S. Roy ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
Nanocomposite Materials ◽  
High Energy Ball Milling ◽  
Iron Nitride ◽  
Energy Ball

Effects of High-Energy Ball Milling Time on the Sintering Process of FeSe Superconductors

2016 ◽  
Vol 848 ◽  
pp. 657-663 ◽  
Author(s):  
Sheng Nan Zhang ◽  
Xiao Bo Ma ◽  
Ji Xing Liu ◽  
Jian Qing Feng ◽  
Cheng Shan Li ◽  
...  
Keyword(s):  
Phase Composition ◽  
Ball Milling ◽  
Optimal Parameter ◽  
High Energy ◽  
Superconducting Phase ◽  
High Energy Ball Milling ◽  
Superconducting Transition ◽  
Sintering Process ◽  
Energy Ball ◽  
Precursor Powders

FeSe superconducting bulks were prepared with high energy ball milling (HEBM) aided sintering process, within which process, tetragonal β-FeSe superconducting phase could be formed directly with one step sintering process, and the formation of hexagonal δ-FeSe non-superconducting phase was effectively avoided. The influences of HEBM time on the sintering process of FeSe bulks were systematically investigated. With different HEBM time, the phase composition and morphology of precursor powders changed correspondingly, which thus influenced the final phase composition and superconducting properties of FeSe superconducting bulks. Due to the formation of FeSe bulks with larger tetragonal phase content and higher superconducting transition temperature, HEBM time of 6.0 h was recognized as the optimal parameter. Shorter HEBM time could lead to the insufficient decrease of particle size and low density. While longer HEBM time caused the formation of amorphous hexagonal δ-FeSe, which crystallized during sintering process. Thus no more tetragonal FeSe could be obtained. The FeSe superconducting bulk with the critical temperature Tc(onset) of 8.0 K was obtained with the HEBM time of 6 h, and sintering temperature of 700 oC for 12 h.

Nanocrystalline Nd2Fe17synthesized by high-energy ball milling: crystal structure, microstructure and magnetic properties

2010 ◽  
Vol 22 (21) ◽  
pp. 216005 ◽  
Author(s):  
Pablo Álvarez ◽  
Pedro Gorria ◽  
Victorino Franco ◽  
Jorge Sánchez Marcos ◽  
María J Pérez ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball ◽  
Microstructure And Magnetic Properties

Al2O3-10 wt% Fe composite prepared by high energy ball milling: Structure and magnetic properties

2021 ◽  
Vol 47 (1) ◽  
pp. 984-991
Author(s):  
Rafael A. Raimundo ◽  
Rayanne S.S. Reinaldo ◽  
Nailton T. Câmara ◽  
Cleber S. Lourenço ◽  
Franciné A. Costa ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Microstructure and thermoelectric properties of Ga-DOPED SiGe alloys prepared by mechanical alloying and induction hot pressing

2014 ◽  
Vol 07 (02) ◽  
pp. 1450008 ◽  
Author(s):  
Shanshan Lin ◽  
Chunlin Wang ◽  
Haiyan Chen ◽  
Dexuan Huo ◽  
Nick Savvides ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hot Pressing ◽  
High Energy ◽  
Solid Solution Phase ◽  
Nominal Composition ◽  
Mill Time ◽  
Composition Property ◽  
Energy Ball ◽  
P Type ◽  
Milled Powders

Ga -doped SiGe alloys were prepared by high energy ball milling followed by induction hot pressing. The grain size decreases dramatically with increasing mill time, and nanostructured features in the range 3–500 nm were introduced after extensive ball milling for 2–12 h. The bulk alloys hot pressed from 2 h and 6 h dry-milled powders consist of different compositions of micron- to nanosized Si y Ge 100-y, where Ga prefers to locate in the submicron- and nanosized Ge -rich phase and form a modulation-doping structure. The samples hot pressed from 12 h wet-milled powders are more homogeneous in microstructure and composition. Property characterization shows that although Ga -doping leads to p-type conduction, only part of Ga atoms is incorporated as dopant in the SiGe solid solution phase. Samples hot pressed from 2 h and 6 h dry-milled powders have higher power factors, while those hot pressed from 12 h wet-milled powders posses much lower thermal conductivity. The maximum figure of merit (ZT) is 0.51 at 805°C for the 6 h dry-milled and hot pressed sample with the nominal composition Si 80 Ge 18 Ga 2.

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