ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Addition of tungsten (1–2 at. %) is very effective in improving coercivity of (Nd,Dy)-(Fe,Co)-B sintered magnets both at room temperature and elevated temperatures in addition to improving thermal stability. Transmission electron microscopy shows that there exists a WFeB precipitate phase inside the Nd2Fe14B (2-14-1) matrix grain. The WFeB phase is plateletlike, and occasionally appears to have its largest dimension running parallel to the c axis of the 2-14-1 matrix phase. The orientation relationship between the WFeB precipitate and the matrix is found to be (102)WFeB(parallel)(220)2-14-1, and [010]WFeB(parallel)[002]2-14-1. Domain walls jump from a position alongside the WFeB particles to a new position alongside others upon turning on magnetic field of the objective lens, as evidenced by Lorentz microscopy, denoting the ability of domain-wall pinning by the strain field around the WFeB precipitate. As a result, this provides extra hindrance to domain-wall motion and leads to enhanced coercivity and thermal stability, particularly at elevated temperatures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.358146
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