scholarly journals Magnetic hardening of soft phase in nanocomposite permanent magnetic materials by exchange coupling

2010 ◽  
Vol 59 (9) ◽  
pp. 6593
Author(s):  
Yin Jin-Hua ◽  
Chen Xi-Fang ◽  
Zhang Shuai ◽  
Zhang Hong-Wei ◽  
Chen Jing-Lan ◽  
...  
Keyword(s):  
Magnetic Materials ◽  
Exchange Coupling ◽  
Soft Phase ◽  
Magnetic Hardening

scholarly journals Ligand-Driven Exchange Coupling in Graphene-Based Magnetic Materials

2016 ◽  
Vol 57 (10) ◽  
pp. 1680-1684 ◽  
Author(s):  
Nguyen Van Thanh ◽  
Nguyen Anh Tuan ◽  
Phạm Thi Tuan Anh ◽  
Nguyen Viet Cuong ◽  
Dam Hieu Chi
Keyword(s):  
Magnetic Materials ◽  
Exchange Coupling

Size-Dependence of Effective Anisotropy and Coercivity in Nanocomposite Permanent Magnetic Materials

2011 ◽  
Vol 217-218 ◽  
pp. 1689-1692
Author(s):  
Jia Jun Guo ◽  
Zhong Wei Wang ◽  
Jian Zhang ◽  
Hong Wei Li ◽  
Xu Zhao ◽  
...  
Keyword(s):  
Grain Size ◽  
Physical Model ◽  
Magnetic Materials ◽  
Exchange Coupling ◽  
Size Dependence ◽  
Strong Dependence ◽  
Statistical Average ◽  
Effective Anisotropy ◽  
Coupling Interaction ◽  
Exchange Coupling Interaction

Take into account different degree of exchange-coupling interaction between soft and hard grains, the effective anisotropy and coercivity in nanocomposite permanent magnetic materials has been investigated by adopting a statistical average physical model. The calculated results show a strong dependence of effective anisotropy and coercivity on the grain size in these materials. Using this model, the serious deterioration of coercivity in experiments especially when the grain size is less then 15nm could be explained in terms of the dramatic drop of the effective anisotropy in nanocomposites.

scholarly journals The effects of the thickness of magnetically hard- and soft-phase layers on magnetic properties and exchange coupling in multilayer magnets

2005 ◽  
Vol 97 (10) ◽  
pp. 10K303 ◽  
Author(s):  
W. Liu ◽  
Y. C. Sui ◽  
J. Zhou ◽  
X. K. Sun ◽  
C. L. Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Soft Phase ◽  
Phase Layers ◽  
Magnetically Hard

scholarly journals Exchange-coupling interaction and effective anisotropy of NdFeB nanocomposite permanent magnetic materials

2004 ◽  
Vol 53 (9) ◽  
pp. 3171
Author(s):  
Feng Wei-Cun ◽  
Gao Ru-Wei ◽  
Han Guang-Bing ◽  
Zhu Ming-Gang ◽  
Li Wei
Keyword(s):  
Magnetic Materials ◽  
Exchange Coupling ◽  
Effective Anisotropy ◽  
Coupling Interaction ◽  
Exchange Coupling Interaction

scholarly journals Cluster-Assembled Iron-Platinum Nanocomposite Permanent Magnets

2006 ◽  
Vol 962 ◽  
Author(s):  
Xiangxin Rui ◽  
Zhiguang Sun ◽  
Yingfan Xu ◽  
David J. Sellmyer ◽  
Jeffrey E. Shield
Keyword(s):  
Exchange Coupling ◽  
Permanent Magnets ◽  
Volume Fraction ◽  
High Energy ◽  
Heat Treatments ◽  
Processing Route ◽  
Soft Magnetic ◽  
Soft Phase ◽  
Energy Product ◽  
Post Deposition

ABSTRACTExchange-spring nanocomposite permanent magnets have received a great deal of attention for their potential for improved the energy products. Predicted results, however, has been elusive. Optimal properties rely on a uniformly fine nanostructure. Particularly, the soft magnetic phase must be below approximately 10 nm to ensure complete exchange coupling. Inert gas condensation (IGC) is an ideal processing route to produce sub-10 nm clusters method. Two distinct nanostructures have been produced. In the first, Fe clusters were embedded in an FePt matrix by alternate deposition from two sources. Fe cluster content ranged from 0 to 30 volume percent. Post-deposition multi-step heat treatments converted the FePt from the A1 to L10 structure. An energy product of approximately 21 MGOe was achieved. Properties deteriorated rapidly at cluster concentrations above 14 volume due to uncoupled soft magnetic regions (from cluster-cluster contacts) and cooperative reversal. The second nanostructure, designed to overcome those disadvantages, involved intra-cluster structuring. Here, Fe-rich Fe-Pt clusters separated by C or SiO2 were fabricated. Phase separation into Fe3Pt and FePt and ordering was induced during post-deposition multi-step heat treatments. By confining the soft and hard phases to individual clusters, full exchange coupling was accomplished and cooperative reversal between clusters was effectively eliminated. An energy product of more than 25 MGOe was achieved, and the volume fraction of the soft phase was increased to greater than 0.5 while maintaining a coercivity of 6.5 kOe. The results provide new insight into developing high energy product nanostructured permanent magnets.

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