ChemInform Abstract: Effect of Heat Treatment of the Microstructure and Magnetic Properties of Niobium-Containing (Nd,Dy)-(Fe,Co)-B Sintered Permanent Magnets.

ChemInform ◽  
1990 ◽  
Vol 21 (20) ◽  
Author(s):  
G. F. ZHOU ◽  
Y. C. CHUANG ◽  
X. K. SUN ◽  
R. GROESSINGER ◽  
H. R. KIRCHMAYR
2010 ◽  
Vol 638-642 ◽  
pp. 1743-1748
Author(s):  
G.J. Chen ◽  
Y.H. Shih ◽  
Jason S.C. Jang ◽  
S.R. Jian ◽  
P.H. Tsai ◽  
...  

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.


2013 ◽  
Vol 54 (10) ◽  
pp. 2007-2010 ◽  
Author(s):  
Keita Shinaji ◽  
Tsuyoshi Mase ◽  
Keita Isogai ◽  
Masashi Matsuura ◽  
Nobuki Tezuka ◽  
...  

2012 ◽  
Vol 516 ◽  
pp. 73-77 ◽  
Author(s):  
Bicheng Chen ◽  
Xingmin Liu ◽  
Renjie Chen ◽  
Shuai Guo ◽  
Don lee ◽  
...  

2016 ◽  
Vol 848 ◽  
pp. 709-714 ◽  
Author(s):  
Gang Fu ◽  
Jiang Wang ◽  
Mao Hua Rong ◽  
Guang Hui Rao ◽  
Huai Ying Zhou

The rare-earth (RE) permanent magnets based on Nd2Fe14B with excellent magnetic properties have been widely used in industrial applications. In this work, the crystal structure, microstructure and magnetic properties of Nd2.28Fe13.58B1.14, Ce2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys prepared by arc-melting were investigated. The results show that all alloys are single phase with tetragonal Nd2Fe14B-type (space group P42/mnm). The Curie temperatures (Tc) of RE2.28Fe13.58B1.14 (RE=Nd, Ce, Pr) alloys are 583 K, 423 K and 557 K, respectively. On the other hand, the coercivities of Nd2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys are about 1.05 T and 1.23 T, respectively, while that of Ce2.28Fe13.58B1.14 alloy is only about 0.25 T due to the poor squareness of hysteresis loop. Meanwhile, the saturation magnetizations of Nd2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys are about 135 emu/g and 113 emu/g, respectively, while that of Ce2.28Fe13.58B1.14 alloy is about 97 emu/g. It was indicated that the Curie temperatures and magnetic properties of RE2.28Fe13.58B1.14 alloys with the same crystal structure are dependent on light rare earth elements.


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