Temperature and strain dependence of the magnetic properties of multilayers with interfacial DMI

Abstract

Magnetic multilayers with perpendicular anisotropy and an interfacial Dzyaloshinskii-Moriya interaction contain chiral domain walls and skyrmions that are promising for applications. Here we measure the temperature dependence of the Dzyaloshinskii-Moriya interaction (DMI) in Pt/CoFeB/Ir and Pt/CoB/Ir multilayers by means of static domain imaging. First, the temperature dependences of saturation magnetisation (MS ), exchange stifness (A) and intrinsic perpendicular anisotropy (Ku) are determined independently, and scaling laws for Ku and D with the magnetisation are established. We then image the demagnetised domain pattern in each multilayer by wide- field Kerr microscopy in the temperature range 9-290 K. We calculate the DMI constant D from an analytical expression for the domain wall energy density that treats the multilayer as a uniform medium.