Temperature dependence of the Dzyaloshinskii-Moriya interaction in Pt/Co/Cu thin film heterostructures

Abstract

Magnetic materials that exhibit chiral domain walls are of great interest for spintronic devices. In this work, we examine the temperature-dependent behavior of the Dzyaloshinskii-Moriya interaction (DMI) in Pt/Co/Cu thin film heterostructures. We extract the DMI strength, D, from static domain spacing analysis between 300 K and 500 K and compare its temperature dependence to that of the magnetic anisotropy, Ku, and saturation magnetization, Ms. Consistent with expected scaling in thin films, Ms exhibits Bloch-law temperature scaling and Ku scales as Ms2.1±0.1. However, D varies more strongly with temperature than expected, scaling as D∝Ms4.9±0.7, indicating that interfacial DMI is more sensitive to thermal fluctuations than bulk magnetic properties. We suggest that this may be related to the temperature dependence of locally induced magnetic moments in the Pt underlayer and the 3d-5d orbital interactions at the interface. While we observe stable domain widths in the studied temperature range, a strongly temperature dependent DMI may have significant consequences for potential devices based on the chiral domain wall or skyrmion motion.