scholarly journals Synthesis of Anisotropic Magnetic Powders Composed of Nanocomposite Hard and Soft magnetic Phases

2006 ◽  
Vol 14 (0) ◽  
pp. 175-177
Author(s):  
Kazuhiko Majima
Keyword(s):  
Soft Magnetic ◽  
Magnetic Phases

First order reversal curve investigation of the hard and soft magnetic phases of annealed CoFeCu nanowire arrays

2013 ◽  
Vol 429 ◽  
pp. 46-51 ◽  
Author(s):  
M. Almasi-Kashi ◽  
A. Ramazani ◽  
E. Golafshan ◽  
M. Arefpour ◽  
E. Jafari-Khamse
Keyword(s):  
Nanowire Arrays ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
First Order

scholarly journals Nanocomposite permanent magnetic materials Nd-Fe-B type: The influence of nanocomposite on magnetic properties

2005 ◽  
Vol 41 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Nadezda Talijan ◽  
Jasna Stajic-Trosic ◽  
Aleksandar Grujic ◽  
Vladan Cosovic ◽  
Vladimir Menushenkov ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Permanent Magnet ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
New Type ◽  
Permanent Magnet Materials

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.

Study on the Nanostructure and Magnetic Properties of NdFeNbB Permanent Magnets

2010 ◽  
Vol 638-642 ◽  
pp. 1749-1754
Author(s):  
X.F. Wang ◽  
X.Y. Chen ◽  
Z.L. Jiang ◽  
Y. Chen ◽  
H.M. Chen
Keyword(s):  
Exchange Coupling ◽  
Permanent Magnets ◽  
Coupling Effect ◽  
Maximum Energy ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
Maximum Energy Product ◽  
Energy Product ◽  
High Maximum ◽  
Intrinsic Coercivity

Nd2Fe14B/-Fe nanocomposite permanent magnet contains the hard and soft magnetic phases, Nd2Fe14B and -Fe respectively. An exchange coupling effect exists between the two magnetic phases. The effect of alloying element Nb on its nanostructure and properties have been studied. Adding Nb to the alloy is effective to refine grains, a relatively small grain size causes a high intrinsic coercivity, remanence and therefore a high maximum energy product, (BH)max. MFM (Magnetic Force Microscope) was used to observe the magnetic micro-domain structure in the nanophase alloys. The length of the magnetic contrast shows a significant dependence on the microstructure and phase constitution, and the longer length is correspond with the larger exchange coupling effect between the soft and hard magnetic phases.

Influence of multiple magnetic phases on the extrinsic damping of FeCo–SiO2 soft magnetic films

2010 ◽  
Vol 107 (3) ◽  
pp. 033911 ◽  
Author(s):  
Bailin Liu ◽  
Yi Yang ◽  
Dongming Tang ◽  
Jiangwei Chen ◽  
Huaixian Lu ◽  
...  
Keyword(s):  
Magnetic Films ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
Soft Magnetic Films

scholarly journals Magnetic Phase Coexistence and Hard–Soft Exchange Coupling in FePt Nanocomposite Magnets

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1618
Author(s):  
O. Crisan ◽  
I. Dan ◽  
P. Palade ◽  
A. D. Crisan ◽  
A. Leca ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Squid Magnetometry ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
X Ray ◽  
Annealing Temperatures ◽  
Nanocomposite Magnets ◽  
Inflection Points

With the aim of demonstrating phase coexistence of two magnetic phases in an intermediate annealing regime and obtaining highly coercive FePt nanocomposite magnets, two alloys of slightly off-equiatomic composition of a binary Fe-Pt system were prepared by dynamic rotation switching and ball milling. The alloys, with a composition Fe53Pt47 and Fe55Pt45, were subsequently annealed at 400 °C and 550 °C and structurally and magnetically characterized by means of X-ray diffraction, 57Fe Mössbauer spectrometry and Superconducting Quantum Interference Device (SQUID) magnetometry measurements. Gradual disorder–order phase transformation and temperature-dependent evolution of the phase structure were monitored using X-ray diffraction of synchrotron radiation. It was shown that for annealing temperatures as low as 400 °C, a predominant, highly ordered L10 phase is formed in both alloys, coexisting with a cubic L12 soft magnetic FePt phase. The coexistence of the two phases is evidenced through all the investigating techniques that we employed. SQUID magnetometry hysteresis loops of samples annealed at 400 °C exhibit inflection points that witness the coexistence of the soft and hard magnetic phases and high values of coercivity and remanence are obtained. For the samples annealed at 500 °C, the hysteresis loops are continuous, without inflection points, witnessing complete exchange coupling of the hard and soft magnetic phases and further enhancement of the coercive field. Maximum energy products comparable with values of current permanent magnets are found for both samples for annealing temperatures as low as 500 °C. These findings demonstrate an interesting method to obtain rare earth-free permanent nanocomposite magnets with hard–soft exchange-coupled magnetic phases.

A layered double hydroxide-derived exchange spring magnet array grown on graphene and its application as an ultrathin electromagnetic wave absorbing material

2019 ◽  
Vol 7 (39) ◽  
pp. 12270-12277 ◽  
Author(s):  
Xiaonan Zhao ◽  
Xiaoyu Nie ◽  
Ya Li ◽  
Yanhui Pu ◽  
Xin Sun ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Soft Magnetic ◽  
Magnetic Phases ◽  
Graphene Composite ◽  
Exchange Spring ◽  
Doped Graphene ◽  
Absorbing Material ◽  
Double Hydroxide

An exchange spring magnet/N-doped graphene composite is synthesized as an ultrathin and highly efficient electromagnetic wave absorbing material utilizing the exchange coupling effect between hard/soft magnetic phases.

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
Keyword(s):  
Magnetic Properties ◽  
Magnetization Reversal ◽  
Exchange Interactions ◽  
Soft Magnetic ◽  
Bulk Alloy ◽  
Saturation Ratio ◽  
Pinning Mechanism ◽  
Magnetic Phases ◽  
Strong Exchange ◽  
Xrd Studies

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.

Electroless Fabrication of Nd-Fe-B/α-Fe Heterostructured Composite Magnets and their Magnetic Properties

2014 ◽  
Vol 809-810 ◽  
pp. 426-432 ◽  
Author(s):  
Xiao Dong Fan ◽  
Na Tian ◽  
Cai Yin You
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Hydrogen Reduction ◽  
Nucleation Mechanism ◽  
Soft Magnetic ◽  
Pinning Mechanism ◽  
Demagnetization Curve ◽  
Magnetic Phases ◽  
Domain Wall Pinning ◽  
Magnetization Processes

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.

scholarly journals EQUILIBRIUM STATES OF SOFT MAGNETIC HEMISPHERICAL SHELL

SPIN ◽  
2013 ◽  
Vol 03 (03) ◽  
pp. 1340003 ◽  
Author(s):  
DENIS D. SHEKA ◽  
VOLODYMYR P. KRAVCHUK ◽  
MYKOLA I. SLOIKA ◽  
YURI GAIDIDEI
Keyword(s):  
Phase Diagram ◽  
Ground State ◽  
Equilibrium States ◽  
Geometrical Parameters ◽  
Soft Magnetic ◽  
Micromagnetic Simulations ◽  
Magnetic Phases ◽  
Hemispherical Shell ◽  
Wide Range ◽  
Magnetic Shell

The ground state of hemispherical permalloy magnetic shell is studied. There exist two magnetic phases: the onion state and the vortex one. The phase diagram is systematically analyzed in a wide range of geometrical parameters. Possible transitions between different phases are analyzed using the combination of analytical calculations and micromagnetic simulations.

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