Eduardo Martínez

Influence of magnetoelectric coupling on electric field induced magnetization reversal in a composite unstrained multiferroic chain

We study theoretically the multiferroic dynamics in a composite one-dimensional system consisting of BaTiO

Spin configuration in a frustrated ferromagnetic/antiferromagnetic thin-film system

{}_{3}

Dynamical depinning of chiral domain walls

multiferroically coupled to an iron chain. The method treats magnetization and polarization as thermodynamic quantities describable via a combination of the Landau-Lifshits-Gilbert and the Ginzburg-Landau dynamics coupled via an additional term in the total free energy density. This term stems from the multiferroic interaction at the interface. For a wide range of strengths of this coupling, we predict the possibility of obtaining a well-developed hysteresis in the ferromagnetic part of the system induced by an external electric field. The dependence of the reversal modes on the electric field frequency is also investigated and we predict a considerable stability of the magnetization reversal for frequencies in the range of 0.5--12 GHz.

Domain wall motion by localized temperature gradients

We have studied the magnetic configuration in ultrathin antiferromagnetic Mn films grown around monoatomic steps on an Fe( 001) surface by spin-polarized scanning tunnelling microscopy/spectroscopy ...

Morphology and magnetism of Fe monolayers and small Fen clusters (n = 2?19) supported on the Ni(111) surface

Comision Europea (P7-PEOPLE-2013-ITN 608031) Gobierno de Espana (MAT2014-52477-C5-4-P) Junta de Castilla y Leon (SA282U14, SA090U16)

Non-collinear magnetism in the Fe3 microcluster: Free-standing vs supported environments

Comision Europea (P7-PEOPLE-2013-ITN 608031) Gobierno de Espana (MAT2014-52477-C5-4-P) Junta de Castilla y Leon (SA282U14 y SA090U16)

Structural characterization of magnetic nanostripes by fast domain wall injection

Using the modified embedded atom model in conjunction with a self-consistent tight-binding method, we investigated the lowest-energy structures of Fe monolayers and isolated Fen clusters (n = 2–19) supported on the Ni(111) surface. In keeping with experimental findings, our calculations predict that the atoms of the monolayer occupy face-centred cubic (fcc) rather than hexagonal close-packed (hcp) sites. Likewise in agreement with experiment we found that Fe layers stack with a pseudomorphic fcc structure up to two monolayers, beyond which they stack as bcc(110). The structures of supported Fe clusters are predicted to be two-dimensional islands maximizing the number of nearest-neighbour bonds among the adsorbed Fe atoms, and their average magnetic moments per atom decrease towards that of the supported Fe monolayer almost monotonically as n increases. Finally, a pair of Fe3 clusters on Ni(111) were found to exhibit virtually no interaction with each other even when separated by only one atomic row, i.e. so long as they do not coalesce they retain their individual magnetic properties.

Spin-polarized scanning tunneling microscopy/spectroscopy study of MnAu(001) thin films

The possibility of a non-collinear magnetic configuration of the Fe3 microcluster supported on the Ni (001) surface has been investigated. The morphology of the supported cluster has been calculated by means of the modified embedded atom model with quenched molecular dynamics simulations, and the electronic structure for the most stable geometrical configuration has been studied using a self-consistent non-collinear spd tight-binding method parameterised to ab-initio tight-binding linear muffin tin orbital results. Our predictions are compared with previous results for the free-standing Fe3 microcluster. The influence of the substrate in both the structure and the magnetic properties, particularly the onset of non-collinear magnetism, is discussed in detail.