In Pursuit of Antiskyrmions and the Anisotropic Dzyaloshinskii-Moriya Interaction: Structural and Magnetic Characterization of Uniaxial Pt/Co-based C2_v Thin Films

Antiskyrmions can potentially be supported by C2_v thin films which permit both Rashba- and Dresselhaus-type Dzyaloshinskii-Moriya interactions (DMI). This work presents C2_v Ag/Pt/Co-based films as potential antiskyrmion hosts. X-ray diffraction 2θ-ω scans of Ag/Pt/Co/Pt films grown epitaxially on Si(110) single crystal substrates show that Co adopts a (10.0) hexagonal closed-packed (hcp) orientation. These findings were corroborated by selected area electron diffraction patterns and further supported by a strong in-plane uniaxial anisotropy measured by alternating gradient field magnetometry. Crosstie domain walls in these films were directly observed by Lorentz transmission electron microscopy, which are also predicted from micromagnetic simulations. To promote perpendicular magnetic anisotropy and a net DMI field in these films, we fabricate thinner, asymmetric Ag/Pt/[Co/Ni]_x/Pt films. X-ray diffraction analysis suggest that the hcp structure is preserved throughout the Ni layers. Structural and magnetic observations of this lower symmetry film stack are compared to micromagnetic simulations. Finally, we discuss approaches to enhancing the expected Dresselhaus-type contribution.