Study of Synthetic Antiferromagnetic Nanostructures Based on CoFeB/Ru/CoFe

Abstract

A study of the magnetic properties of synthetic antiferromagnetic nanostructures (SAF) has been carried out. In the SAF structure, two ferromagnetic layers separated by a nonmagnetic metal are coupled by the exchange RKKY interaction (Ruderman— Kittel—Kasuya—Yoshida), which has an oscillating character. The total magnetic moment of the SAF structure is minimal with an antiparallel configuration of the magnetization of the ferromagnetic layers, due to which the effect on the magnetic layers in the structure is reduced. The structures under study have a number of unique properties and are used in the elements of nonvolatile magnetoresistive memory, in magnetic field transducers, and in spin logic devices. The characteristics of the SAF of CoFeB/Ru/CoFe nanostructures with the Ru layer thickness corresponding to the second antiferromagnetic maximum are obtained. The magnetization reversal curves of SAF structures with Ru thickness of 2.1 nm, 2.3 nm and 2.5 nm have been studied. The optimal ratio of ferromagnetic layers was selected to reduce the magnetic moment of the SAF structure. A study of the effect of thermomagnetic treatment on the properties of the SAF nanostructure was carried out, which showed that there are no significant changes in the magnetization reversal, and the magnetic saturation field slightly increases. The curves of magnetization reversal of CoFeB/Ru/CoFe structures fixed by the antiferromagnetic layer are presented. In addition, magnetization reversal curves of spin-tunnel magnetoresistive nanostructures with an antiferromagnetic layer and a SAF structure are presented, and an analysis of the thermal stability of the structures with SAF is also carried out.