Multiscale simulations applied to the study of magnetic and structural properties of transition metal nanostructures

Focused on the study of nanostructured systems of magnetic materials, the aim is to carry out a systematic study that allows the structural and magnetic characterization of nanometric-sized systems of magnetic materials such as Fe, Ni, Co with different geometries. Through Multiscale theoretical-computational simulations, first principles calculations, Monte Carlo simulations and Molecular Dynamics are integrated in order to obtain the magnetic properties of this type of systems and thus make a valuable contribution to the generation of scientific knowledge in the area of nanoscience . In the first instance we want to investigate the structural and magnetic electronic properties of magnetic materials (Fe, Ni, Co). In this stage we will also analyze the effect of hydrogen impurities on the structural, electrical and magnetic properties of these systems. Likewise, we will study the interaction between the surfaces of the materials in order to obtain a more precise data of the values of the exchange constant for the case of interfaces of different materials; and thereby obtain the empirical potentials that will be used for calculations in molecular dynamics. In this way, once the necessary constants have been obtained from the first principles calculations and the thermally stable structures from molecular dynamics, we will perform the Monte Carlo simulations to calculate the thermodynamic properties as a function of size, geometry and temperature. Among the expected results are of course those of academic relevance, such as the behavior of the thermodynamic and magnetic properties for the different systems studied, which must be in correspondence with the results found experimentally. In addition, the values of the coupling constants at the interface of bimetallic systems. With these results, the corresponding scientific dissemination products will be written, to be published in internationally recognized and indexed ISI-type scientific journals and the subsequent dissemination will be carried out in national and international scientific events.

Carry out a systematic study that allows the structural and magnetic characterization of nanometric-sized structures with geometry of nanocylinders, spheres and core-shell structures of magnetic materials through theoretical-computational simulations based on multiscale modeling that allow making a valuable contribution to the generation of scientific knowledge in the area of nanoscience.Specific objectives1.Develop computer programs for the construction of structures with geometries of interest (nanocylinders, spheres, Core-Shell and nanoparticles). 2.Study the electronic, magnetic and structural properties of Fe, Ni, Co systems and the interfaces of combined systems using first principles methods in order to obtain the minimum energy structures and the values of the magnetic parameters necessary for the simulations at a higher scale.3.Obtain the influence of impurities such as hydrogen on the magnetic and structural properties of transition metal systems.4.Study, by means of molecular dynamics simulations, the most thermally and magnetically stable structures of nanometric sizes. 5.Study the magnetic properties of Fe, Ni, Co systems and combined Fe-Ni, Fe-Co systems with geometries of interest by using Fast MC methods and molecular dynamics.6.Study Core-Shell type systems of the studied materials that present Exchange Bias effect.

It is expected to find the effect of geometry, size and impurities on the magnetic properties of mentioned nanostructures. On the one hand, it will be possible to construct the magnetic phase diagrams based on the geometric parameters and, at the same time, show the role that dipolar energy plays in the formation of magnetic configurations. Additionally, by adding interstitial impurities in magnetic systems, it is expected to see noticeable changes in minimum energy structures and magnetic properties, since these impurities are non-magnetic, but they provide electron redistributions that strongly influence the magnetism of these systems. Our contribution hopes to show much more realistic aspects in the Exchange fields and in general in the magnetic properties of systems that present Exchange Bias effect in order to evaluate the effect of the interface on the magnetic properties of Core-Shell nanostructures. already established in the simulation d e nanostructured materials and solid state physics. Likewise, the final results are expected to be published in high-impact ISI-SCOPUS-type journals and to participate in international events of high interest in this field.