Performance of metallic antiferromagnets for use in spin-valve read sensors

A summary of the electrical, magnetic and corrosion properties of Mn-based metallic antiferromagnets for use in spin-valve devices is presented. Two families are considered. One is the family of FeMn, IrMn and others having a fcc structure. They are in the antiferromagnetic phase in the as-deposited state. The other is the family of NiMn, PtMn and others which do require a high temperature anneal and large thickness in order to undergo a phase transformation into an antiferromagnetic fct lattice. Alloying Mn with precious metals such as Pt or Pd leads to the best corrosion properties, superior even to permalloy.