Reorientation in Antiferromagnetic Multilayers: Spin-Flop Transition and Surface Effects

Recent research works have shown that the magnetic order in some antiferromagnetic materials can be manipulated and detected electrically, due to two physical mechanisms: Neel-order spin-orbit torques and anisotropic magnetoresistance. While these observations open up opportunities to use antiferromagnets for magnetic memory devices, different physical characterization methods are required for a better understanding of those mechanisms. Here we report a magnetic field induced...

We explore the role of interfacial antiferromagnetic interaction in coupled soft and hard ferromagnetic layers to ascribe the complex variety of magneto-transport phenomena observed in $La_{0.7}Sr_{0.3}MnO_3/SrRuO_3$ (LSMO/SRO) superlattices (SLs) within a one-band double exchange model using Monte-Carlo simulations. Our calculations incorporate the magneto-crystalline anisotropy interactions and super-exchange interactions of the constituent materials, and two types of antif...

The interaction between superconductivity and ferromagnetism in thin film superconductor/ferromagnet heterostructures is usually reflected by a change in superconductivity of the S layer set by the magnetic state of the F layers. Here we report the converse effect: transformation of the magnetocrystalline anisotropy of a single Fe(001) layer, and thus its preferred magnetization orientation, driven by the superconductivity of an underlying V layer through a spin-orbit coupled...

Development of modern spintronic devices requires materials exhibiting specific magnetic effects. In this paper, we investigate a magnetization reversal mechanism in a [Co/Pdx]7/CoO/[Co/Pdy]7 thin-film composite where an antiferromagnet is sandwiched between a hard and a soft ferromagnets with different coercivities. The antiferromagnet/ferromagnet interfaces give rise to the exchange bias effect. The application of soft and hard ferromagnetic films causes exchange-spring-lik...

Antiferromagnetic materials are magnetic inside, however, the direction of their ordered microscopic moments alternates between individual atomic sites. The resulting zero net magnetic moment makes magnetism in antiferromagnets invisible on the outside. It also implies that if information was stored in antiferromagnetic moments it would be insensitive to disturbing external magnetic fields, and the antiferromagnetic element would not affect magnetically its neighbors no matte...

We present a comprehensive study of the exchange bias effect in a model system. Through numerical analysis of the exchange bias and coercive fields as a function of the antiferromagnetic layer thickness we deduce the absolute value of the averaged anisotropy constant of the antiferromagnet. We show that the anisotropy of IrMn exhibits a finite size effect as a function of thickness. The interfacial spin disorder involved in the data analysis is further supported by the observ...

Antiferromagnetic chains with an odd number of spins are known to undergo a transition from an antiparallel to a spin-flop configuration when subjected to an increasing magnetic field. We show that in the presence of an anisotropy favoring alignment perpendicular to the field, the spin-flop state appears for both weak and strong field, the antiparallel state appearing for intermediate fields. Both transitions are second order, the configuration varying continuously with the f...

Although the development of spintronic devices has advanced significantly over the past decade with the use of ferromagnetic materials, the extensive implementation of such devices has been limited by the notable drawbacks of these materials. Antiferromagnets claim to resolve many of these shortcomings leading to faster, smaller, more energy-efficient, and more robust electronics. Antiferromagnets exhibit many desirable properties including zero net magnetization, imperviousn...

By studying coupled ferro- (FM) and antiferromagnetic (AFM) thin film systems, we obtain an in-plane magnetic reorientation as a function of temperature and FM film thickness. The interlayer exchange coupling causes a uniaxial anisotropy, which may compete with the intrinsic anisotropy of the FM film. Depending on the latter the total in-plane anisotropy of the FM film is either enhanced or reduced. Eventually a change of sign occurs, resulting in an in-plane magnetic reorien...

The ground state and the finite temperature phase diagrams with respect to magnetic configurations are studied systematically for thin magnetic films in terms of a classical Heisenberg model including magnetic dipole-dipole interaction and uniaxial anisotropy. Simple relations are derived for the occurrence of the various phase boundaries between the different regions of the magnetic orientations. In particular, the range of the first and second order reorientation phase tran...