Unraveling oscillations at ferro(para)magnetic and non-collinear antiferromagnetic interfaces

Abstract

Here, we show that the ferro(para)magnetic and non-collinear antiferromagnetic interfaces contribute to oscillating signals observed in the magnetoresistance. We associate the effect with the fact that the spins on the surface of IrMn\(_3\) produce instability in the surface magnetoresistance of the material, which is sensitive to the magnetic field. We carried out experiments using bilayers of IrMn\(_3\) under permalloy (Py) and IrMn\(_3\) under platinum (Pt). The oscillations were intensely evident at the Py/IrMn\(_3\) interface and less explicit at the Pt/IrMn\(_3\) interface. We carried out the experiments using pulsed current, with a square pulse width of 1 \(\mu \)s and amplitudes of \(I_{AC}\) = 20 \(\mu \)A to 20 mA. The oscillating signals are proportional to the crystallographic direction of the material, the ferromagnetism of the material adjacent to IrMn\(_3\), and sensitive to the amplitude of the pulsed current. We believe that observation is a way of transmitting encoded information through magnetoresistance.