Temperature-induced reversal of magnetic interlayer exchange coupling

TL;DR

This study investigates how temperature can reverse the sign of magnetic interlayer exchange coupling in Gd/Tb/Y trilayers, revealing a temperature-dependent mechanism affecting magnetic interactions.

Contribution

It demonstrates a temperature-induced sign reversal of IEC in rare-earth trilayers, a phenomenon not previously reported, linked to electron reflectivities at magnetic interfaces.

Findings

IEC oscillates with spacer thickness

Temperature causes sign reversal of IEC

Reversal linked to electron reflectivities

Abstract

For epitaxial trilayers of the magnetic rare-earth metals Gd and Tb, exchange coupled through a non-magnetic Y spacer layer, element-specific hysteresis loops were recorded by the x-ray magneto-optical Kerr effect at the rare-earth $M_5$ thresholds. This allowed us to quantitatively determine the strength of interlayer exchange coupling (IEC). In addition to the expected oscillatory behavior as a function of spacer-layer thickness $d_Y$, a temperature-induced sign reversal of IEC was observed for constant $d_Y$, arising from magnetization-dependent electron reflectivities at the magnetic interfaces.