Exchange Bias in La0.67Sr0.33MnO3/YFeO3 Ferromagnet/Antiferromagnet Multilayer Heterostructures

Abstract

Exchange bias (EB), manifested as a hysteresis-loop offset after field-cooling,is demonstrated in perovskite-structured ferromagnet/antiferromagnet(La 0.67 Sr 0.33 MnO3 /YFeO3 )n heterostructures grown on (100) SrTiO3substrates. Bilayer samples show an EB of 306 Oe at 50 K, whereas multilayerswith five layers exhibit an exchange bias of up to 424 Oe at 50 K. A spin valveconsisting of La 0.67 Sr 0.33 MnO3 /SrTiO3 /La 0.67 Sr 0.33 MnO3 /YFeO3 shows stableremanent configurations resulting from pinning of the upper La0.67 Sr 0.33 MnO3layer by the YFeO3 . In contrast, EB is not observed on (111)-oriented SrTiO3substrates due to interface roughening. These results demonstrate YFeO3 asan alternative orthoferrite antiferromagnet compared to BiFeO 3 and LaFeO3for incorporation into exchange-biased heterostructures.