The emerging field of antiferromagnetic spintronics consists in exploring spin-dependent properties of antiferromagnetic materials. This class of magnetic materials might offer a number of advantages in terms of new physics and device performance due to: i) robustness against external magnetic fields, ii) zero net magnetization which produces no stray field, and iii) high frequency dynamics, typically close to THz frequencies. Besides the interesting features mentioned above, antiferromagnets are found to show a wide variety of properties. As far as electrical properties are concerned, they can be metals, insulators, semimetals, semiconductors and also superconductors. This makes antiferromagnets interesting for spintronic devices and intense research effort have been carried out recently in order to demonstrate the specific properties of antiferromagnets. In this thesis manuscript, we present how we explored experimentally novel spin and charge transport mechanism in ferromagnetic and antiferromagnetic spin structures and spin textures. Via the spin pumping technique, we unravelled the spin transport mechanisms associated with magnetic ordering transitions in materials with different electrical states and have studied the role of the electronic or magnonic nature of the spin current. In addition to that, we have studied spin-charge conversion in ferromagnets and antiferromagnets. We also used magnetotransport experiments to demonstrate spin-dependent properties specific to the antiferromagnetic arrangement of spins, where we have observed a spontaneous Hall effect that relies in crystal and magnetic symmetries. Finally, we evaluated whether magnetic textures in antiferromagnets matter for transport, whether it be single electron or Cooper pair transport. Particularly, we have used the proximity effect to study Cooper pair characteristic lengths in antiferromagnets. We have also explored the replication of spin textures from ferromagnets to antiferromagnets to reveal to what extend it is possible to control those textures in antiferromagnets.

https://www.spintec.fr/phd-defense-exploring-novel-spin-and-charge-transport-mechanism-in-ferromagnetic-and-antiferromagnetic-spin-structures-and-spin-textures/