Magnetic multilayers with perpendicular anisotropy and an interfacial Dzyaloshinskii-Moriya interaction (DMI) contain chiral domain walls and skyrmions that are promising for applications. Here, we measure the temperature dependence of the DMI in Pt/CoFeB/Ir and Pt/CoB/Ir multilayers by means of static domain imaging. First, the temperature dependences of saturation magnetization $\left(M_{\mathrm{S}}\right)$, exchange stiffness $\left(A\right)$, and intrinsic perpendicular anisotropy $\left(K_{\mathrm{u}}\right)$ are determined. Then the demagnetized domain pattern in each multilayer is imaged by wide-field Kerr microscopy in the temperature range 9–290 K, and the characteristic domain period at each temperature is determined. We calculate the DMI constant $D$ from an analytical expression for the domain wall energy density that treats the multilayer as a uniform medium. Scaling laws for $K_{\mathrm{u}}$ and $D$ with the magnetization are established from the experiments. While the scaling of $K_{\mathrm{u}}$ is consistent with Callen-Callen theory, we find that the scaling of $D$ is like that of $A$ predicted theoretically $(\sim 1.8)$.

• Received 19 August 2021
• Accepted 15 November 2021

DOI:https://doi.org/10.1103/PhysRevB.104.224402