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 IrMn3 produce instability in the surface magnetoresistance of the material, which is sensitive to the magnetic field. We carried out experiments using bilayers of IrMn3 under permalloy (Py) and IrMn3 under platinum (Pt). The oscillations were intensely evident at the Py/IrMn3 interface and less explicit at the Pt/IrMn3 interface. We carried out the experiments using pulsed current, with a square pulse width of 1μs and amplitudes of 20 μA to 20 mA. The oscillating signals are proportional to the crystallographic direction of the material, the ferromagnetism of the material adjacent to IrMn3, and sensitive to the amplitude of the pulsed current. We believe that observation is a way of transmitting encoded information through magnetoresistance.