Rare earth permanent magnets

Rare earth permanent magnets with no slip and not subject to decoupling. 

Nelmses, R. J., Loveday, E., Kaldis, E. Karpinski, J. (1992) Physica C 172, 311. Nesbitt, E. A. Wernick, J. H. (1973) Rare Earth Permanent Magnets, Academic Press, New York. 

Soubeyroux, J.L., Fruchart, D., Isnard, O., Miraglia, S., Tomey, E. (1995) Role of the (H, C, N) interstitial elements on the magnetic properties of iron-rare earth permanent magnet alloys, J.Alloys Comp. 219, 16-24. 

Nesbitt, E. A., Wernick, J. H. Rare earth permanent magnets. Academic Press New York 1973. 

The specific power of rare earth permanent magnet motors can exceed 1 kW/kg. The combination of reliable, low-cost, solid-state controllers and brushless permanent magnet motors will find applications in (i) computer accessories like disk drives, printers, x-y plotters, (ii) consumer goods like hand tools, fans, and air-conditioners, (iii) robotics, traction motors, steel mills, lift motors, and (iv) aerospace flight control actuators. 

Nesbitt, E.A., Wernick, J.H. Rare Earth Permanent Magnets. New York Academic Press 1973. 

Fig. 38. Schematic representation of the various process steps in the manufacture of sintered rare earth permanent magnets. (After Ormerod 1985.)...

Fidler, J., ed., 1982, Proc. 6th Int. Workshop on Rare Earth Permanent Magnets and their Applications, Baden (Technical University of Vienna, Austria). 

Ray, A.E., 1986b, in Proc. Rare Earth Permanent Magnet Workshop, 27-28 January 1986, ed. J. Hurt (US Army Research Office, Research Triangle Park, NC, USA). 

Ormerod, J. (1985). The physical metallurgy and processing of sintered rare earth permanent magnets. Journal of Less Common Metals, 1,49-69. 

Some aspects of fundamental research on rare-earth permanent magnetic... 

The most obvious characteristic of the rare-earth magnets is that these compounds are fundamentally metallic alloys between rare earths and transition metals. A recent trend in the development of rare-earth permanent magnets is the use of a third element, such as B in Nd2FeuB and N in Sm2Fei7N3. 

The rare-earth permanent magnets were bom by combining the high magnetization of the transition-metal sublattice with the high crystalline anisotropy of the lanthanide... 

Materials for rare-earth permanent magnets and their typical properties... 

We conclude that the cooling velocity in the rapid solidification process has a strong relationship with the reaction velocity and/or the velocity of the movement of solidification fronts, which decides the stable phase under the given conditions. More attention, therefore, should be paid to the reaction velocity of phase formation for controlling the microstructures of the rare-earth permanent magnets. 

Rare-earth permanent magnets are known to show much better magnetic properties compared to conventional Al-Ni-Co and ferrite magnets. Initially, Sm-Co magnets such as SmCos (Hubbard et al., 1960) and Sm2Coi7 (Tawara... 

E. A. Nesbitt and J. H, Wernick, Rare Earth Permanent Magnets, 1973 W. E. Wallace, Rare Earth Intermetallics, 1973 7. C. Phillips, Bonds and Bands in Semiconductors, 1973 H. Schmalzried, Solid State Reactions, 1974... 

More recent high-tech developments, e.g., the preparation of high-temperature superconducting oxides, rare-earth permanent magnets, magnetic-resonance contrast agents, and rare-earth phosphors, require fairly to very pure supplies of individual lanthanides. In addition to these very spedlic applications, essentially all of the scientific advances made in the understanding of the chemistry and material science of the lanthanides have been made because of the availability of pure samples of the individual lanthanides and their salts. Separation chemistry plays a central role to the availability of these pure samples. 

The application of mechanical alloying to the synthesis of rare-earth permanent magnets was first demonstrated by the work of Schultz and co-workers (Schultz et al. 1987). Subsequently, the magnetic properties of a number of rare-earth-transition-metal compounds synthesized by the mechanical alloying of elemental powders, mechanical milling of intermetallic compounds, or by mechanochemical reaction, using oxide and halide precursors, have been studied. 

Magnetic properties of mechanically alloyed rare earth permanent magnet alloys... 

---