Internal temperature compensation of rare earth-cobalt permanent magnets for microwave devices by adding heavy lanthanides

Abstract

The temperature variation of the remanent flux of rare earth-transition metal permanent magnets can be minimized by making appropriate substitutions of heavy lanthanides in the alloy. The underlying physical principle, its use in sintered magnets and some problems and limitations are reviewed. Recent successful applications to 2–17-type magnets are discussed. Difficulties in using the concept of temperature coefficient are outlined.