X-ray Magnetic Linear Dichroism Studies of Electrical Switching of Antiferromagnetic Order in α-Fe2O3 Epitaxial Films

Abstract

Recently manipulation of antiferromagnetic (AFM) order has been gaining the attention of the spintronics community [1]. Magnetic switching has been reported in AFM thin films based on electronic transport methods, which provide only spatially averaged information on AFM states. Other techniques, such as x- ray magnetic linear dichroism (XMLD) microscopy, can provide local information on AFM domains. In this study, we report the direct observation of spin reorientation in response to current pulses in (0001)-oriented α-Fe2O3 films [2,3]. Our experiment combines the application of current pulses and spatially resolved photoemission electron microscopy (PEEM) with XMLD to detect AFM contrast. Pulses were applied in two different configurations A and B (Fig. 1a), which results in resistance changes (Fig. 1b), and XMLD images were taken before and after the application of a current pulse to reveal changes in the AFM domains (Fig. 1c). Our analysis shows that electrical pulses do not only reorient the Néel vector within the easy plane as previous work indicates [2,3]. Instead, we conclude that most of the change associated with the Néel vector is out of the film plane and different pulse directions can bring the AFM order in and out of the plane deterministically. This work is supported in part by the Air Force Office of Scientific Research under Grant FA9550- 19-1-0307.