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.

scholarly journals Nanocrystalline Nd-Fe-B Alloys for Polymer-Bonded Magnets Production

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Aleksandar Grujić ◽  
Vladan Ćosović ◽  
Aleksandar Ćosović ◽  
Jasna Stajić-Trošić
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Magnetic Phase ◽  
Coupling Effect ◽  
Maximum Energy ◽  
Soft Magnetic ◽  
Nanocomposite Structure ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Composite Production

This study presents how different nanostructures of starting Nd-Fe-B particles have influence on magnetic properties of polymer-bonded Nd-Fe-B materials. Two types of nanocrystalline Nd-Fe-B alloys were used for polymer composite production by compression molding technique. The particles with low neodymium content (Nd-low) have nanocomposite structure with small exchange coupling effect between hard and soft magnetic phase. In other hand, practically monophase hard magnetic structure of Nd-Fe-B particles with stoichiometric neodymium content (Nd-stoich) shows improved magnetic properties. With increasing concentration of polymer matrix, the coercivity (Hcb), remanence (Br), and maximum energy product ((BH)max) decrease more prominenty for composites with stoichiometric Nd-Fe-B content.

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.

scholarly journals Methods of characterization of multiphase Nd-Fe-B melt-spun alloys

2007 ◽  
Vol 39 (2) ◽  
pp. 193-198 ◽  
Author(s):  
A. Grujic ◽  
V. Cosovic ◽  
J. Stajic-Trosic ◽  
A. Maricic ◽  
N. Talijan
Keyword(s):  
Magnetic Material ◽  
Exchange Coupling ◽  
Permanent Magnets ◽  
Coupling Effect ◽  
Melt Spun ◽  
Methods And Techniques ◽  
New Type ◽  
Insight Into ◽  
Microstructure And Magnetic Properties

Nanocomposite permanent magnetic materials based on Nd-Fe-B alloys with a low Nd content are a new type of permanent magnetic material. The microstructure of these nanocomposite permanent magnets is composed of a mixture of magnetically soft and hard phases providing the so called exchange coupling effect. Beside the optimization process parameters, methods of characterization have a very important role in the design of an optimal magnetic matrix of multiphase melt-spun Nd-Fe-B alloys. Different methods and techniques of characterization were used for observation and study of the microstructure evolution during crystallization. A summary results of measurements using different methods of characterization are presented to enable a better insight into relations between the microstructure and magnetic properties of the investigated melt-spun Nd-Fe-B alloys. .

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.

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.

Effects of Heat Treatment Conditions on Magnetic Properties and Structural Features of Nanocrystalline Fe79Zr10N11 Films

2009 ◽  
Vol 152-153 ◽  
pp. 70-74 ◽  
Author(s):  
E.N. Sheftel ◽  
Rauf S. Iskhakov ◽  
S.V. Komogortsev ◽  
P.K. Sidorenko ◽  
Nikolai S. Perov
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Structural Features ◽  
Soft Magnetic ◽  
Exchange Correlation ◽  
Calculation Technique ◽  
Treatment Conditions ◽  
Random Magnetic Anisotropy ◽  
Anisotropy Model

Data on the random magnetic anisotropy and exchange correlation length in soft magnetic nanocrystalline Fe79Zr10N11 films were obtained using a calculation technique in frame of the random magnetic anisotropy model. The calculations are performed using approach magnetization to saturation curves. The local magnetic anisotropy fields (Ha), and magnetic anisotropy correlation radii (Rс) reduced to =(A/K)1/2 were determined for the films annealed at 475 and 6000 C for 0.5, 1, 2, and 3 h. The correlation Hc ~(Rc/)3 for the all annealed films was found.

Magnetic Properties of Rapidly Quenched Soft Magnetic Co-Based Alloy Subjected to Heat Treatment in a Sulfur Atmosphere

2021 ◽  
Vol 122 (1) ◽  
pp. 1-5
Author(s):  
A. A. Feshchenko ◽  
N. A. Kulesh ◽  
E. A. Mikhalitsina ◽  
D. S. Neznakhin ◽  
N. V. Selezneva ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Soft Magnetic ◽  
Sulfur Atmosphere
Sign in / Sign up

Export Citation Format

Share Document