Khulaif Alshammari, Eloi Haltz, Mohammed Alyami, Mannan Ali, Paul S. Keatley, Christopher H. Marrows, Joseph Barker, Thomas A. Moore

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 $(\sim 1.8)$.