Structure, Magnetic Properties and Magnetization Reversal Processes in Nanocrystalline Pr8Dy1Fe60Co7Mn6B14Zr1Ti3 Bulk Alloy

2019 ◽  
Vol 70 (11) ◽  
pp. 4086-4088 ◽  
Author(s):  
Anna Przybyl ◽  
Izabela Wnuk ◽  
Jerzy J. Wyslocki

The present paper presents results concerning on structure, magnetic properties and magnetization reversal processes in the as-cast Pr8Dy1Fe60Co7Mn6B14Zr1Ti3 alloy in the form of 1 mm plate. The XRD studies revealed coexistence of three phases dominant Pr2(Fe,Co)14B and minor �-Fe and Fe3B. The remanence-to-saturation ratio Jr/Js equaled 0.66 and indicated on existence of strong exchange interactions between hard and soft magnetic phases. The analysis of Mrev vs. Mirr dependences, the pinning mechanism was detected in studied alloy.

2019 ◽  
Vol 70 (11) ◽  
pp. 4086-4088

The present paper presents results concerning on structure, magnetic properties and magnetization reversal processes in the as-cast Pr8Dy1Fe60Co7Mn6B14Zr1Ti3 alloy in the form of 1 mm plate. The XRD studies revealed coexistence of three phases dominant Pr2(Fe,Co)14B and minor á-Fe and Fe3B. The remanence-to-saturation ratio Jr/Js equaled 0.66 and indicated on existence of strong exchange interactions between hard and soft magnetic phases. The analysis of Mrev vs. Mirr dependences, the pinning mechanism was detected in studied alloy. Keywords: bulk alloys, magnetic properties, magnetization reversal processes


2014 ◽  
Vol 809-810 ◽  
pp. 426-432 ◽  
Author(s):  
Xiao Dong Fan ◽  
Na Tian ◽  
Cai Yin You

Electroless plating was used to coat Fe layers on the hard magnetic Nd-Fe-B powders to fabricate Nd-Fe-B/α-Fe heterostructured magnetic powders. The heat treatment was performed to study the property evolution of the heterostructured magnetic powders. The results show that Fe coating was oxidized to Fe2O3while drying; through the hydrogen reduction annealing, Fe2O3was reduced to α-Fe. The coercivity of the heterostructured magnetic powders increased from 111.3 kA/m (1.4 kOe) to 524.7 kA/m (6.6 kOe) after annealing at 650°C. However, the demagnetization curve of powders presents a kink due to un-ideal coupling between hard and soft magnetic phases because of the aggregation of α-Fe. The magnetization processes of the heterostructured powders transferred from the dominant nucleation mechanism to domain wall pinning mechanism after the heat treatment.


2005 ◽  
Vol 41 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Nadezda Talijan ◽  
Jasna Stajic-Trosic ◽  
Aleksandar Grujic ◽  
Vladan Cosovic ◽  
Vladimir Menushenkov ◽  
...  

The influence on the magnetic properties of nanocristalline ribbons and powders has character of microstructure, between others ? the grain size volume of hard and soft magnetic phases and their distribution. Magnetic properties of ribbons and powders depend mainly on their chemical composition and parameters of their heat treatment [1]. Technology of magnets from nanocristalline ribbon consists of the following process: preparing the Nd-Fe- B alloy, preparing the ribbon, powdering of the ribbon, heat treatment of the powder and finally preparing the magnets. Nanocomposite permanent magnet materials based on Nd-Fe- B alloy with Nd low content are a new type of permanent magnetic material. The microstructure of this nanocomposite permanent magnet is composed of a mixture of magnetically soft and hard phases which provide so called exchange coupling effect.


2005 ◽  
Vol 475-479 ◽  
pp. 2127-2130
Author(s):  
Xiaoqian Bao ◽  
Mao Cai Zhang ◽  
Yi Qiao ◽  
Shouzeng Zhou

Nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons were prepared by melt-spinning and subsequent annealing. Interaction domains were imaged using magnetic force microscopy (MFM) because of strong exchange coupling between hard and soft magnetic grains. Coercivity was determined by exchange coupling pinning field. But the magnetization reversal of nanocomposite magnets were different from that of traditional single phase permanent magnets.


1996 ◽  
Vol 35 (Part 2, No. 1A) ◽  
pp. L19-L22 ◽  
Author(s):  
Akinori Kojima ◽  
Akihiro Makino ◽  
Yoshihito Kawamura ◽  
Tsuyoshi Masumoto

2019 ◽  
Vol 56 (4) ◽  
pp. 1008-1012
Author(s):  
Bartlomiej Jez ◽  
Marcin Nabia�ek ◽  
Kinga Jez

Iron-based amorphous alloys are characterized by so-called soft magnetic properties. Unfortunately, the geometry of iron-based amorphous materials significantly limits the applicability of these materials. One way to expand the use of these materials is to make composites based on them. As part of this work, rapid-cooled alloys were produced using the injection casting method. On their basis, magnetic composites with the addition of a non-magnetic binder were produced. The results of the structure (XRD) and magnetic properties (VSM) tests of the produced materials are presented. The research results have shown that the decisive impact on the magnetic properties of composites is the fact of the separation of magnetic particles with a non-magnetic binder. In this case, the influence of exchange interactions is dominated by dipole interactions.


1983 ◽  
Vol 27 ◽  
Author(s):  
N. C. Koon ◽  
D. Weber ◽  
P. Pehrsson ◽  
A. I. Schindler

ABSTRACTWe have measured the magnetic properties of highly oriented pyrolytic graphite (HOPG), polyethylene (PE), and polyvinylidine fluoride (PVF2), implanted with fluences of 25 keV iron atoms ranging from 1016 to 1017 atoms/cm2 . The lowest fluence specimens were paramagnetic down to 2 K, with evidence for clusters of only a few spins, while the highest fluence specimens were clearly ferromagnetic, with magnetization curves resembling those of a set of randomly oriented soft magnetic planes. The critical fluence for formation of a ferromagnetic state appears to be between 1 and 3 × 1016 atoms/cm2 at 25 keV. Theseresults can be qualitatively understood based on the critical density for percolation of near neighbor exchange interactions.


Author(s):  
June D. Kim

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.


1998 ◽  
Vol 22 (4_1) ◽  
pp. 186-189
Author(s):  
M. Matsumoto ◽  
A. Morisako ◽  
Y. Mutoh

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