Arthur von Hippel and Magnetism

Abstract

AbstractThis article examines the role that Arthur von Hippel played in magnetism work in the 1950s.Von Hippel understood that the ferrimagnetic insulators represented by the ferrospinels, magnetoplumbites, and ferrogarnets were critical for the high-frequency technology that was being developed after World War II. At the Laboratory for Insulation Research at MIT, he and his students concentrated on the response of these materials to electric and magnetic excitations over a wide frequency range that extended, with gaps, from dc to the ultraviolet. For magnetic studies, he used microwave frequencies to obtain resonance and relaxation data that could be interpreted because the magnetic spins are relatively loosely coupled to their surroundings. He supplemented these resonance studies with classical magnetometer, transport, and x-ray diffraction measurements on single-crystal samples in order to obtain fundamental information that would aid in the design of materials for technical applications.