Growth and Antiferromagnetic Properties of Epitaxial RuO2 Thin Films

Recent studies of RuO₂ have challenged the previously accepted characterization of it as a Pauli paramagnet, suggesting antiferromagnetic ordering in both bulk and thin-film samples. The rutile structure of RuO₂, in conjunction with its magnetic ordering, breaks PT symmetry (alter-magnetism), making it an intriguing candidate for antiferromagnetic spintronics. However, the existence of magnetic domains complicates the understanding, and presents challenges for spintronic applications.

We have grown high-quality epitaxial RuO₂ thin films on TiO₂ substrates in multiple orientations: (001), (100), (111), (110), and (101). Our process provides the potential to produce thin films with spins either in or out of the plane, and to investigate the thickness dependence of Neel vector orientation. Our preliminary findings suggest that applying current during cooling through the Neel temperature could facilitate the creation of a monodomain state, paving the way for a deeper understanding of RuO2 towards its potential applications in spintronic devices.