Samarium-cobalt magnets

Samarium (Sm), 74 631t, 634t electronic configuration, 1 41 At Samarium-cobalt magnets, 74 651 Sampatrilat, 5 159... 

In the early 1970 s when samarium-cobalt magnets were first being proposed as a replacement for platinum-cobalt in microwave tubes, few could have anticipated the success that was to follow. Notwithstanding the traumas brought about by a quadrupling of cobalt prices, their use has grown steadily to the point where they now command a vitally important position in the permanent magnet market. 

Phosphor manufacture is still a dominant factor for suppliers of rare earth chemicals. According to industry sources (29), approximately 1/3 of the monetary volume of rare earth chemicals is used by the electronics industry. Included in this figure is Sm O for samarium-cobalt magnets. The remainder includes Gd O, La.,0 and Tb 0, for x-ray and lighting phosphors, and Y O ana... 

The production of samarium cobalt magnets requires lhe use of calcium. The reaction is... 

Samarium cobalt magnets have three to six times greater magnetic energy than alnicn magnets. 

The samarium-cobalt magnets were discovered in the 1960s. Its performance made it possible to obtain intense magnetic energy in low volume, and subsequently, miniaturization utilized in timing motors, or, even more spectacularly, in audiovisuals where the use of the Sm-Co magnet, for example, made it possible to refine the miniature earphones used with Walkman s. 

Alnico alloys in permanent magnets with e.g. 10% Al, 18% Ni, 12% Co, 6% Cu and 54% Fe. See further samarium-cobalt magnets in chapter 17 Rare Earth Metals ... 

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