Magnetic materials for dry reed contacts

Dry reed contacts typically fall into two categories, the nonself-latching and the self-latching types. Historically, the nonself-latching was the first developed and Fe-Ni alloys have found wide acceptance as the reed material. More recently, the self-latching contact has received widespread attention from the communications industry, motivated by potential reductions in physical size and energy consumption. This has stimulated studies into new magnetic alloy development and into material processing modifications, on both newly developed as well as previously known alloys, to meet the stringent properties requirements. The emphasis of this review is on the self-latching contact focusing on its requirements, the magnetic materials which have the potential to meet these requirements, and the sometimes intricate processing steps which have been developed to realize the potential. Alloys in the Co-Fe-Nb, Co-Fe-V, Co-Fe-Ni-Al, and several other families which are principally precipitation-type permanent-magnet materials are considered.