Towards hexagonal $C_{2v}$ systems with anisotropic DMI: Characterization of epitaxial Co$(10\bar{1}0)$/Pt$(110)$ multilayer films

TL;DR

This paper investigates a new epitaxial Co/Pt multilayer system with $C_{2v}$ symmetry, strong in-plane uniaxial anisotropy, and potential for hosting anisotropic DMI and novel chiral spin textures.

Contribution

It introduces a novel epitaxial relationship in Co/Pt multilayers that supports strong uniaxial anisotropy and anisotropic DMI, advancing the understanding of chiral spin textures in such systems.

Findings

Characterized the crystal structure and magnetic properties of Co/Pt multilayers.

Established a correlation between stacking faults and magnetocrystalline anisotropy.

Proposed this system as a promising platform for exploring new spin configurations.

Abstract

Ferromagnet/heavy metal (FM/HM) multilayer thin films with $C_{2v}$ symmetry have the potential to host antiskyrmions and other chiral spin textures via an anisotropic Dzyaloshinkii-Moriya interaction (DMI). Here, we present a candidate material system that also has a strong uniaxial magnetocrystalline anisotropy aligned in the plane of the film. This system is based on a new Co/Pt epitaxial relationship, which is the central focus of this work: hexagonal closed-packed Co$(10\bar{1}0)[0001]$ $\parallel$ face-centered cubic Pt$(110)[001]$. We characterized the crystal structure and magnetic properties of our films using X-ray diffraction techniques and magnetometry respectively, including q-scans to determine stacking fault densities and their correlation with the measured magnetocrystalline anisotropy constant and thickness of Co. In future ultrathin multilayer films, we expect this epitaxial relationship to further enable an anisotropic DMI while supporting interfacial perpendicular magnetic anisotropy. The anticipated confluence of these properties, along with the tunability of multilayer films, make this material system a promising testbed for unveiling new spin configurations in FM/HM films.