Optimization of Nanocomposite Materials for Permanent Magnets: Micromagnetic Simulations of the Effects of Intergrain Exchange and the Shapes of Hard Grains

Abstract

Making the strongest magnets from the cheapest, most readily available materials is of keen interest in producing electric motors for cars, for example. In this study, advanced simulations illustrate the potential for $a$ $p\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}i$ optimization of nanocomposite materials for permanent magnets. In particular, these simulations reveal that---in contrast to common belief---either perfect exchange coupling between magnetically soft and hard phases, or an elongated shape for hard grains, can seriously $r\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}e$ the performance of the resulting magnets.