High-field polar MOKE magnetometry as a probe of interlayer exchange coupling in MBE-grown Co/Cu/Co(111) and Fe/Cr/Fe(001) wedged trilayers

Abstract

We discuss the use of room temperature polar magneto-optic Kerr effect (MOKE) measurements at high field (≤7 T) in investigating antiferromagnetic (AFM) and ferromagnetic (FM) exchange coupling in MBE-grown wedged trilayers. In the case of Co/Cu/Co(111), the polar MOKE revealed the first AFM coupling peak at 9 Å Cu thickness and the second weaker AFM coupling peak at 20 Å. This is an important result because it helps in resolving the present controversy over whether oscillatory coupling exists in (111) oriented MBE-grown Co/Cu/Co structures. For Fe/Cr/Fe(001), polar MOKE is found to be less sensitive than in-plane MOKE for extracting the detailed form of the coupling. However, polar MOKE reveals additional variations in the perpendicular saturation fields as a function of interlayer thickness, which are not found in the in-plane MOKE saturation fields.