Microstructure analysis of Nd-Fe-B sintered magnets improved by Tb-metal vapour sorption

被引：46
作者：
Watanabe, N. [1 ]
Umemoto, H. [1 ]
Ishimaru, M. [1 ]
Itakura, M. [1 ]
Nishida, M. [1 ]
Machida, K. [2 ]
机构：
[1] Kyushu Univ, Dept Appl Sci Elect & Mat, Fukuoka 8168580, Japan
[2] Osaka Univ, Ctr Adv Sci & Innovat, Suita, Osaka 5650871, Japan
来源：
JOURNAL OF MICROSCOPY | 2009年 / 236卷 / 02期
关键词：
Amorphous; wetting-layer; energy dispersive X-ray spectroscopy (EDS); grain boundary; terbium; transmission electron microscopy (TEM); PHASE;
D O I：
10.1111/j.1365-2818.2009.03231.x
中图分类号：
TH742 [显微镜];
学科分类号：
摘要：
P>Behaviours of constituent elements in the Nd-Fe-B sintered magnets improved by Tb-metal vapour sorption have been investigated by using an analytical transmission microscopy. It was found that a triple junction of the grain boundaries consists of fine Nd-O crystalline and amorphous phase. The energy dispersive X-ray spectroscopy (EDS) analysis showed that the amorphous phase mainly consists of Co, Nd and Tb. The Tb-treatment causes the formation of the amorphous Co-Nd(Tb) wetting-layer phase which wraps each Nd2Fe14B grain. The results suggest that the wrapped structure prevents the nucleation of magnetic reversed domains and then improves significantly the coercivity of the magnet.
引用
收藏
页码：104 / 108
页数：5
相关论文
共 11 条
  • [1] De Boer F.R., 1989, COHESION METALS TRAN
  • [2] ANALYSIS OF HYSTERESIS LOOPS IN ND-FE-B SINTERED MAGNETS
    GIVORD, D
    TENAUD, P
    VIADIEU, T
    [J]. JOURNAL OF APPLIED PHYSICS, 1986, 60 (09) : 3263 - 3265
  • [3] Machida K-I, 2005, COLL ABSTR MAGN SOC, V142, P25
  • [4] Phase boundary structure in Nd-Fe-B sintered magnets
    Makita, K
    Yamashita, O
    [J]. APPLIED PHYSICS LETTERS, 1999, 74 (14) : 2056 - 2058
  • [5] Okamoto H., 2000, DESK HDB PHASE DIAGR
  • [6] ON THE GRAIN-BOUNDARY PHASE IN IRON RARE-EARTH BORON MAGNETS
    RAMESH, R
    CHEN, JK
    THOMAS, G
    [J]. JOURNAL OF APPLIED PHYSICS, 1987, 61 (08) : 2993 - 2998
  • [7] Transmission electron microscopy study on Nd-rich phase and grain boundary structure of Nd-Fe-B sintered magnets
    Shinba, Y
    Konno, TJ
    Ishikawa, K
    Hiraga, K
    Sagawa, M
    [J]. JOURNAL OF APPLIED PHYSICS, 2005, 97 (05)
  • [8] Suzuki S., 2003, MAT INTEGRATION, V16, P17
  • [9] Improvement of coercivity of sintered NdFeB permanent magnets by heat treatment
    Vial, F
    Joly, F
    Nevalainen, E
    Sagawa, M
    Hiraga, K
    Park, KT
    [J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2002, 242 : 1329 - 1334
  • [10] In situ TEM study of Nd-rich phase in NdFeB magnet
    Wang, SC
    Li, Y
    [J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2005, 285 (1-2) : 177 - 182
12