HIGH MAGNETIC PROPERTIES OF TbCu7-TYPE MELT SPUN (Sm, Pr)Co7-xHfxCy RIBBONS

2008 ◽  
Vol 01 (03) ◽  
pp. 183-187 ◽  
Author(s):  
H. W. CHANG ◽  
S. T. HUANG ◽  
I. W. CHEN ◽  
C. W. CHANG ◽  
W. C. CHANG
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Anisotropy Field ◽  
Phase Evolution ◽  
Phase Constitution ◽  
Melt Spun

The effects of Hf substitution and C content on the magnetic properties, phase evolution and microstructure of melt spun ( Sm , Pr ) Co 7-x Hf x C y (x = 0–0.5; y = 0–0.14) ribbons have been studied. A proper Hf substitution is helpful not only in stabilizing 1:7 phase but also in enhancing its magnetic anisotropy field, as a result, magnetic properties of B r = 6.4 kG , i H c = 7.3 kOe and (BH) max = 8.7 MGOe for SmCo 6.9 Hf 0.1 ribbons are obtained. Besides, a small amount of C addition in the ribbons could slightly modify phase constitution and effectively refine their microstructure to strengthen the exchange coupling effect between magnetic grains. It leads to the improvement of the magnetic properties for SmCo 6.8 Hf 0.2 C 0.12 nanocomposites. Finally, a slight Pr substitution for Sm may further increase the magnetization and the magnetic properties, the optimal magnetic properties of B r = 7.1 kG , i H c = 8.5 kOe and (BH) max = 11.2 MGOe could be achieved for the directly quenched Sm 0.8 Pr 0.2 Co 6.9 Hf 0.1 C 0.12 ribbons.

PHASE EVOLUTION AND MAGNETIC PROPERTIES OF TbCu7-TYPE (Sm, Pr)Co7-xHfxMy (x = 0-0.5; y = 0-0.14) RIBBONS

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1663-1669 ◽  
Author(s):  
H. W. Chang ◽  
S. T. Huang ◽  
I. W. Chen ◽  
C. W. Chang ◽  
W. C. Chang
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Anisotropy Field ◽  
Phase Evolution ◽  
Phase Constitution ◽  
Melt Spun

The effects of Hf substitution and C content on the magnetic properties, phase evolution, and microstructure of melt spun ( Sm , Pr ) Co 7- x Hf x C y ( x = 0-0.5; y = 0-0.14) ribbons have been studied. A proper Hf substitution is helpful not only in stabilizing 1:7 phase but also in enhancing its magnetic anisotropy field. As a result, magnetic properties of B r = 6.4 kG , i H c = 7.3 kOe and ( BH ) max = 8.7 MGOe for SmCo 6.9 Hf 0.1 ribbons are obtained. Besides, a small amount of C addition in the ribbons could slightly modify phase constitution and effectively refine their microstructure to strengthen the exchange coupling effect between magnetic grains. Furthermore, a slight Pr substitution for Sm may further increase the magnetization and the magnetic properties of the ribbons. The optimal magnetic properties of B r = 7.1 kG , i H c = 8.5 kOe and ( BH ) max = 11.2 MGOe could be achieved for the directly quenched Sm 0.8 Pr 0.2 Co 6.9 Hf 0.1 C 0.12 ribbons.

Improvement of microwave magnetic properties by inserting nonmagnetic layer

2017 ◽  
Vol 31 (02) ◽  
pp. 1750004
Author(s):  
Xiaoting Li ◽  
Chao An ◽  
Zhen Wang ◽  
Chunlong Xu ◽  
Gang Shi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Resonance Frequency ◽  
Exchange Coupling ◽  
Sandwich Structure ◽  
Anisotropy Field ◽  
Interface Energy ◽  
Coupling Energy ◽  
Radio Frequency Sputtering ◽  
Nonmagnetic Layer

Co/NM (nonmagnetic Ag and SiO2)/Co sandwich structure films with different thicknesses of NM were fabricated on Si(111) substrate via oblique radio frequency sputtering. With increasing thickness of nonmagnetic Ag [Formula: see text], in-plane magnetic anisotropy field [Formula: see text] initially increased from 100 Oe of [Formula: see text] nm to 220 Oe of [Formula: see text] nm, and then decreased when [Formula: see text] nm. Resonance frequency showed the same tendency with maximum 5.2 GHz when [Formula: see text] nm. Damp factor increased from 0.02 for [Formula: see text] for [Formula: see text] nm. The same result was observed in inserting oxide nonmagnetic SiO2 layer. This can be attributed to the competition between interface energy and exchange coupling energy.

MAGNETIC PROPERTIES AND CRYSTAL STRUCTURE OF MELT SPUN Sm(Co, M)7 RIBBONS (M = Hf, V, Nb, andTa)

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3707-3716 ◽  
Author(s):  
H. W. CHANG ◽  
C. C. HSIEH ◽  
Z. H. GUO ◽  
S. T. HUANG ◽  
W. C. CHANG
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Anisotropy Field ◽  
Experimental Results ◽  
Element Substitution ◽  
Melt Spun

Magnetic properties and crystal structure of melt spun SmCo 7-x M x ( M = Hf , V , Nb , and Ta ; x = 0–0.3) ribbons have been investigated. The experimental results showed that not just Hf but also V , Nb and Ta prefer to occupy 2e site in the TbCu 7 structure and remarkably increase coercivity of the ribbons from 1.7 kOe for x = 0 to 10–12 kOe for x = 0.2, which would be due to the increase of magnetic anisotropy field by the element substitution. Furthermore, the effect of C addition on the magnetic properties and microstructure of melt spun Sm ( Co , M )7 ribbons were also studied. A small amount of C addition in the ribbons could effectively refine their microstructure, and leads to further improvement of the magnetic properties. The optimal magnetic properties of B r = 6.9 kG , i H c = 11.8 kOe and ( BH ) max = 10.6 MGOe were attained for SmCo 6.8 Hf 0.2 C 0.12 nanocomposites.

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

Effect of C addition on the magnetic properties, phase evolution, and microstructure of melt spun ribbons

2008 ◽  
Vol 147 (1-2) ◽  
pp. 69-73 ◽  
Author(s):  
H.W. Chang ◽  
S.T. Huang ◽  
C.W. Chang ◽  
W.C. Chang ◽  
A.C. Sun ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Evolution ◽  
Melt Spun ◽  
Melt Spun Ribbons

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.

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.

Magnetic properties, phase evolution, and microstructure of melt-spun (Sm1−xPrx)Co7−yHfyCz (x=0–1; y=0.1–0.3; z=0–0.14) ribbons

2008 ◽  
Vol 103 (7) ◽  
pp. 07E112 ◽  
Author(s):  
H. W. Chang ◽  
I. W. Chen ◽  
C. W. Chang ◽  
Y. K. Fang ◽  
C. C. Hsieh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Evolution ◽  
Melt Spun
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