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Production of high magnetic fields for materials research
The Materials Science Laboratory of the Faculty of Engineering in the Universidad de Talca is working in studying magnetic properties of materials. A permanent magnet (PM) is a very special device because it is essentially an energy storage device. PMs have long occupied a prominent position in technology. Among a prodigious variety of products employing PMs are televisions, telephones, computers, NMR equipment, videocassettes and audio systems, household appliances and automobiles. Since many decades alnico and hard ferrite PM materials were of commercial importance. In recent years, there have been dramatic improvements in the energy product and coercivity of hard magnetic materials. A new era in PM technology has been initiated in 1966 by the development of rare-earth permanent magnets (REPMs), based in samarium-cobalt.

Groups in Japan and in United States discovered in 1983 a new, highly magnetic, material containing neodymium, iron and boron. The new magnetic material, Nd2Fe14B, did not contain the expensive and rare cobalt, a major constituent of the previous best hard PMs, based on SmCo5 and Sm2Co17. In spite of their high energy product, the Sm-Co and Nd-Fe-B based PM have some drawbacks which still provide additional challenges to materials scientists. Particularly, REPM are relatively expensive to manufacture and Nd-Fe-B material has a relative low Curie Temperature (593K). Then, there is a lot of scientific and technological problems to solve and the future of research in hard magnetic materials seems bright. To study REPM in our Laboratory at the Universidad de Talca, a magnetizer with several coils for different poles configurations will be developed. To magnetize a PM, the energy should be pumped into the material through a very strong magnetic field. In REPMs which can show remanent fields of 1 T or more, magnetizing strength of over 12 T are necessary and, energy densities of about 1 kJ per cubic centimeter are required. Therefore, the development of transient electrical systems can bealso useful to be implemented in a transient magnetizers, in which a capacitive discharge in a magnetic circuit can be used to produce very high magnetic fields during millisecond pulse.

A goal of this research has been the production and study of magnetization of REPMs. A device for the task has been constructed and is now under operation.