Effect of Wheel Speeds on the Microstructure and Magnetic Properties of Melt-Spun (Nd0.75,Dy0.25)10.5 Zr2Fe82B5.5 Ribbons

2012 ◽  
Vol 569 ◽  
pp. 23-26 ◽  
Author(s):  
Jie Qiu ◽  
Shan Dong Li ◽  
Mei Mei Liu ◽  
Jian Peng Wu ◽  
Yi Hu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
Wheel Speed ◽  
Coupling Interaction ◽  
Nanocomposite Structure ◽  
Melt Spun ◽  
Exchange Coupling Interaction ◽  
Strong Exchange ◽  
Microstructure And Magnetic Properties

Nanocomposite (Nd,Dy)2Fe14B/α-Fe magnets were prepared by directly solidification (DS). The effect of wheel speed on the magnetic properties, microstructure and exchange coupling interaction has been studied. It was found that a uniform R2Fe14B/α-Fe nanocomposite structure with fine α-Fe grains can be developed at an optimum wheel speed of about 18 m/s. Without any heat treatment, the optimal ribbons (v = 18 m/s) show a strong exchange coupling interaction and good magnetic properties, e.g. iHc=1027 kA/m, mr =0.71, (BH)max=174 kJ/m3.

Prepared and Study of Low Cost and High Performance Nanocomposite (Nd,Dy,Pr)-(Fe,Nb,Zr)-B/α-Fe

2013 ◽  
Vol 647 ◽  
pp. 777-782
Author(s):  
Jin Jiang Hu ◽  
Chen Pu Li ◽  
Chao Liu
Keyword(s):  
Magnetic Properties ◽  
High Performance ◽  
Magnetic Phase ◽  
Low Cost ◽  
Wheel Speed ◽  
Interaction Domain ◽  
Axis Parallel ◽  
Exchange Coupling Interaction ◽  
Strong Exchange ◽  
Microstructure And Magnetic Properties

The microstructure and magnetic properties of melt-spun nanocomposite (Nd, Dy, Pr)-(Fe,Nb,Zr)-B /α-Fe ribbons have been investigated by XRD, SPM and VSM. The ribbons were prepared at a wheel speed range of 10-30 m/s. The multigrain domain or interaction domain was observed in the samples prepared at 20 m/s wheel speed. The easy magnetized direction c-axis parallel to the ribbon plane for the sample prepared at the wheel speed of 20m/s. The average gain size in this sample is about 18nm and the sample consists of hard magnetic phase (Nd, Dy, Pr) 2(Fe,Nb,Zr)14B and sofe magnetic phase α-Fe, there is strong exchange-coupling interaction between them. The magnetic properties obtained are Br=1.28T，Hci= 504.2kA•m-1，(BH)max= 157.8 kJ•m-3，Mr/Ms =0.76.

scholarly journals Microstructure and Magnetic Properties of Highly Ordered SBA-15 Nanocomposites Modified withFe2O3andCo3O4Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
P. F. Wang ◽  
H. X. Jin ◽  
M. Chen ◽  
D. F. Jin ◽  
B. Hong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Exchange Coupling ◽  
Sol Gel ◽  
Coupling Interaction ◽  
A Value ◽  
Hydrothermal Processes ◽  
Exchange Coupling Interaction ◽  
Microstructure And Magnetic Properties

Owing to the unique order mesopores, mesoporous SBA-15 could be used as the carrier of the magnetic nanoparticles. The magnetic nanoparticles in the frame and the mesopores lead to the exchange-coupling interaction or other interactions, which could improve the magnetic properties of SBA-15 nanocomposites. Mesoporous Fe/SBA-15 had been prepared via in situ anchoring Fe2O3into the frame and the micropores of SBA-15 using the sol-gel and hydrothermal processes. Co3O4nanoparticles had been impregnated into the mesopores of Fe/SBA-15 to form mesoporous Fe/SBA-15-Co3O4nanocomposites. XRD, HRTEM, VSM, and N2physisorption isotherms were used to characterize the mesostructure and magnetic properties of the SBA-15 nanocomposites, and all results indicated that the Fe2O3nanoparticles presented into the frame and micropores, while the Co3O4nanoparticles existed inside the mesopores of Fe/SBA-15. Furthermore, the magnetic properties of SBA-15 could be conveniently adjusted by the Fe2O3and Co3O4magnetic nanoparticles. Fe/SBA-15 exhibited ferromagnetic properties, while the impregnation of Co3O4nanoparticles greatly improved the coercivity with a value of 1424.6 Oe, which was much higher than that of Fe/SBA-15.

Preparation and Magnetic Properties of the Core-Nanoshell Composite Materials Doped with Nd

2011 ◽  
Vol 284-286 ◽  
pp. 1956-1960
Author(s):  
Ru Xin Che ◽  
Chun Xia Wang ◽  
Bing Yu
Keyword(s):  
Magnetic Properties ◽  
Composite Materials ◽  
Fly Ash ◽  
Exchange Coupling ◽  
Magnetic Loss ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Coupling Interaction ◽  
The Core ◽  
Exchange Coupling Interaction

The core-nanoshell composite materials doped with Nd were prepared by a solid-state reaction method. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with Nd. The thermal decomposition process of the sample was investigated by TG- DTA. The morphology and composition of the composite materials were investigated by the X-ray diffraction analysis ( XRD ), scanning electron microscope ( SEM ) and energy disperse spectroscopy ( EDS ). The results of vibrating sample magnetometer ( VSM ) analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating. The exchange-coupling interaction enhances magnetic loss of composite materials. The results show that doped with Nd can enhance the coercivity too, so the magnetic properties could be promoted further. The magnetic properties of the core-nanoshell composite material are better than that of single-phase.

scholarly journals Amorphization, Crystallization, and Magnetic Properties of Melt-Spun SmCo7−x(Cr3C2)x Alloys

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Liya Li ◽  
Wei Xie
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Melt Spinning ◽  
Amorphous State ◽  
Wheel Surface ◽  
Amorphous Phases ◽  
Annealed Ribbon ◽  
Melt Spun ◽  
Interaction Domains ◽  
Strong Exchange

Effects of Cr3C2 content and wheel surface speed on the amorphous formation ability and magnetic properties have been investigated for melt-spun SmCo7−x(Cr3C2)x (x=0.10-0.25) alloys. Ribbon melt-spun at lower wheel speed (30 m/s) has composite structure composed of mostly SmCo7, a small amount of Sm2Co17, and residual amorphous phases. The grain size of SmCo7 phase decreases with the increase of Cr3C2 content x. When melt spinning at 40 m/s, SmCo7−x(Cr3C2)x alloys can be obtained in the amorphous state for 0.15≤x≤0.25 with intrinsic coercive Hci of the order of 40–70 Oe. DSC analysis reveals that SmCo7 phase first precipitates from the amorphous matrix at 650∘C, followed by the crystallization of Sm2Co17 phase at 770∘C. Optimal coercivity Hci of 7.98 kOe and remanent magnetization Mr of 55.05 emu/g have been realized in SmCo6.8(Cr3C2)0.20 magnet subjected to melt spinning at 40 m/s and annealing at 650∘C for 5 min. The domain structure of the annealed ribbon is composed of interaction domains typically 100–400 nm in size, which indicates the presence of a strong exchange coupling between the grains.

Microstructure and magnetic properties in as-cast and melt spun Co–Zr alloys

2015 ◽  
Vol 644 ◽  
pp. 7-12 ◽  
Author(s):  
Mithun Palit ◽  
J. Arout Chelvane ◽  
Himalay Basumatary ◽  
D. Aravindha Babu ◽  
S.V. Kamat
Keyword(s):  
Magnetic Properties ◽  
Melt Spun ◽  
Microstructure And Magnetic Properties ◽  
Zr Alloys
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