Giant exchange bias field above room temperature in perovskite YbCr1−xFexO3 (x = 0.6–0.9)

Abstract

Temperature-induced exchange bias is observed in perovskite YbCr_1−xFe_xO₃ (x = 0.6–0.9) compounds. This is ascribed to the ferromagnetic (FM) coupling between Fe³⁺/Cr³⁺ ions and Yb³⁺ ions. During demagnetization, the Yb³⁺ ions will show a tendency to rotate with the direction of the applied magnetic field. However, the antiferromagnetic coupling of Fe³⁺/Cr³⁺ ions has a pinning effect, hindering their rotation, and thus producing an exchange bias effect. With increasing Fe³⁺ ion content, the magnetization and exchange bias field gradually become larger. When x = 0.8 and 0.9, the exchange bias field reaches up to −9.7 kOe and −13.6 kOe at 300 K, respectively. This giant room temperature exchange bias field will be more conducive for practical applications in magnetoelectronic devices.