Temperature Dependence of the Exchange Anisotropy of a GdFeCo Ferrimagnetic Film Coupled to the IrMn Antiferromagnet

The uniaxial anisotropy and kinetics of the transformation of the domain structure in a ferrimagnetic GdFeCo film exchange-coupled to the IrMn antiferromagnet have been studied in a wide temperature range. Ta/Pt/GdFeCo/IrMn/Pt multilayer structures with perpendicular magnetic anisotropy demonstrate the compensation of the sublattice magnetization at K and K. Nonmonotonic temperature dependences of the exchange bias field H-EX and coercivity H-C are revealed. It is established that the slope of the dependence and the quantity H-EX change sign at T-1. An orientational phase transition is detected at a temperature of T-CR = 35 K, below which uniaxial anisotropy, as well as the mechanism of coercive force formation, changes.