Exchange anisotropy in Fe-Nd-B magnets
Creators
- 1. TDK Corp., Research and Development Center, 15-7 Higashi-Owada, 2-chome, Ichikawa, Chiba (Japan)
- 2. Massachusetts Inst. of Tech., Cambridge, MA (USA). Dept. of Materials Science and Engineering
Description
Large exchange anisotropy (1.0 to 1.5 kOe) has been observed by magnetooptic Kerr effect (MOKE) at the surface of Fe-Nd-B sintered magnets. Three samples Fe79-xNd13+xB8 with x = 0, 1, and 2 atom %, were studied. These materials showed bulk intrinsic coercivities of 0.3, 4.2, and 7.7 kOe respectively. All samples showed MOKE coercivities below 0.6 kOe. Only the x = 1 sample exhibited significant MOKE exchange anisotropy. A three-layer model is assumed near the surface: outermost, nonmagnetic Nd2O3, soft Fe-rich subsurface layer, and magnetically hard Fe14Nd2B bulk. The authors speculate that the bulk is exchange-coupled to the soft Fe-rich layer in the x = 0, 1 samples but not in the x = 2 sample because of the greater Nd content of the grain boundaries for x = 2. This explains both the low bulk coercivity in x = 0 and x = 1 and the observation of exchange anisotropy for x = 1 but not for x = 2
Additional details
Publishing Information
- Journal Title
- IEEE Transactions on Magnetics
- Journal Volume
- 26
- Journal Issue
- 1
- Series
- IEEE Trans. Magn.
- Journal Page Range
- 250-252
- ISSN
- 0018-9464
- CODEN
- IEMGA
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 21070348
- Subject category
- S36: MATERIALS SCIENCE; S36: MATERIALS SCIENCE; S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Descriptors DEI
- ANISOTROPY; BORON ALLOYS; COERCIVE FORCE; ELECTRON-HOLE COUPLING; GRAIN BOUNDARIES; IRON; IRON ALLOYS; KERR EFFECT; LAYERS; MAGNETIC PROPERTIES; MAGNETO-OPTICAL EFFECTS; MAGNETS; NEODYMIUM ALLOYS; SINTERING
- Descriptors DEC
- ALLOYS; COUPLING; CRYSTAL STRUCTURE; DIELECTRIC PROPERTIES; ELECTRICAL PROPERTIES; ELEMENTS; EQUIPMENT; FABRICATION; METALS; MICROSTRUCTURE; PHYSICAL PROPERTIES; RARE EARTH ALLOYS; TRANSITION ELEMENTS