A5056764571- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- Multiferroics and related materials
- Magnetic and transport properties of perovskites and related materials
- Acoustic Wave Resonator Technologies
- Magnetic properties of thin films
- Advanced Chemical Physics Studies
- Semiconductor materials and devices
- Physics of Superconductivity and Magnetism
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Advanced Condensed Matter Physics
- Chalcogenide Semiconductor Thin Films
- Surface and Thin Film Phenomena
- Theoretical and Computational Physics
- Perovskite Materials and Applications
- 2D Materials and Applications
- Solid-state spectroscopy and crystallography
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Crystal Structures and Properties
- Machine Learning in Materials Science
- Material Dynamics and Properties
- Phase-change materials and chalcogenides
- Crystallography and molecular interactions
Universidad de Cantabria
2016-2025
Universidad de Alcalá
2020
Rutgers, The State University of New Jersey
2003-2007
University of Geneva
2005
University of Liège
2002-2003
Universidad Autónoma de Madrid
1999-2003
Queen's University Belfast
2001
Universidad de Oviedo
1999
We have developed and implemented a self-consistent density functional method using standard norm-conserving pseudopotentials flexible, numerical LCAO basis set, which includes multiple-zeta polarization orbitals. Exchange correlation are treated with the local spin or generalized gradient approximations. The functions electron projected on real-space grid, in order to calculate Hartree exchange-correlation potentials matrix elements, number of operations that scales linearly size system....
The performance of basis sets made numerical atomic orbitals is explored in density-functional calculations solids and molecules. With the aim optimizing quality while maintaining strict localization orbitals, as needed for linear-scaling calculations, several schemes have been tried. best obtained generated according to a new scheme presented here, flexibilization previous proposals. are tested versus converged plane-wave on significant variety systems, including covalent, ionic metallic....
Recent developments in and around the SIESTA method of first-principles simulation condensed matter are described reviewed, with emphasis on (i) applicability for large varied systems, (ii) efficient basis sets standards accuracy density-functional methods, (iii) new implementations, (iv) extensions beyond ground-state calculations.
A review of the present status, recent enhancements, and applicability SIESTA program is presented. Since its debut in mid-nineties, SIESTA's flexibility, efficiency free distribution has given advanced materials simulation capabilities to many groups worldwide. The core methodological scheme combines finite-support pseudo-atomic orbitals as basis sets, norm-conserving pseudopotentials, a real-space grid for representation charge density potentials computation their associated matrix...
Significance Many natural structures exhibit chirality that is essential to their functional interactions, yet the chiral electronic found in condensed matter systems have been primarily limited magnetic materials. Notably, electric dipole equivalent of skyrmions has remained conspicuously elusive. However, recent theoretical predictions and experimental observations continuous rotation polarization titanate superlattices suggests such complex oxide nanocomposites are ideal candidates for...
Topology provides a framework for an understanding of emergent phenomena in various fields such as the appearance new results field ferroelectrics. A historical introduction and primer on concepts topology are followed by discussion experimental theoretical methods that elucidate exotic textures appear polar oxide nanostructures superlattices. The complex interplay several fundamental processes occurring different energy scales leads to ground states compete with one another have large...
Nonlinear optics reveal how the chirality of ferroelectric vortices can be deterministically controlled using an electric field.
Polar skyrmions are predicted to emerge from the interplay of elastic, electrostatic and gradient energies, in contrast key role anti-symmetric Dzyalozhinskii-Moriya interaction magnetic skyrmions. Here, we explore reversible transition a skyrmion state (topological charge -1) two-dimensional, tetratic lattice merons (with topological -1/2) upon varying temperature elastic boundary conditions [(PbTiO3)16/(SrTiO3)16]8 membranes. This phase is accompanied by change chirality, zero-net...
The evolution of tetragonality with thickness has been probed in epitaxial $c$-axis oriented ${\mathrm{P}\mathrm{b}\mathrm{T}\mathrm{i}\mathrm{O}}_{3}$ films thicknesses ranging from 500 down to $24\text{ }\text{ }\AA{}$. High resolution x ray pointed out a systematic decrease the lattice parameter decreasing film below $200\text{ Using first-principles model Hamiltonian approach, is related reduction polarization attributed presence residual unscreened depolarizing field. It shown that...
Basis sets of atomic orbitals are very efficient for density functional calculations but lack a systematic variational convergence. We present method to optimize numerical variationally, using single parameter control their range. The efficiency the basis generation scheme is tested and compared with other schemes multiple $\ensuremath{\zeta}$ sets. shown be comparable in quality widely used albeit offering better performance linear-scaling computations.
Using first-principles density-functional calculations, gold monatomic wires are found to exhibit a zigzag shape which remains under tension, becoming linear just before breaking. At room temperature they spin, explains the extremely long apparent interatomic distances shown by electron microscopy. The structure is stable if tension relieved, wire holding its chainlike even as free-standing cluster. This unexpected metallic-wire stiffness stems from transverse quantization in wire, simple free model.
We present a first-principles-based (second-principles) scheme that permits large-scale materials simulations including both atomic and electronic degrees of freedom on the same footing. The method is based predictive quantum-mechanical theory, e.g., Density Functional Theory, its accuracy can be systematically improved at very modest computational cost. Our approach dividing electron density system into reference part - typically corresponding to system's neutral, geometry-dependent ground...
Based on recent advances in first-principles theory, we develop a general model of the band offset at metal/ferroelectric interfaces. We show that, depending polarization film, pathological regime might occur where metallic carriers populate energy bands insulator, making it metallic. As most common approximations density functional theory are affected by systematic underestimation fundamental gap insulators, this scenario is likely to be an artifact simulation. provide number rigorous...
The performance of ferroelectric devices is intimately entwined with the structure and dynamics domains. In ultrathin ferroelectrics, ordered nanodomains arise naturally in response to presence a depolarizing field give rise highly inhomogeneous polarization structural profiles. Ferroelectric superlattices offer unique way engineering desired nanodomain by modifying strength electrostatic interactions between different layers. Through combination X-ray diffraction, transmission electron...
Our second-principles results illustrate a strategy for obtaining topological electric textures akin to magnetic skyrmions.
Antimony sulfide, Sb
Lithium, declared critical raw material by the European Union in 2020, is a competitor to hydrogen as alternative petroleum. Its use increasing while reserves are declining, boosting new sources, seawater desalination concentrates. In this work, computational study of most promising extractants, β-diketones and organophosphates combinations thereof, towards lithium presence metal ions found concentrates, Na+, K+, Mg2+, Ca2+ Sr2+ was carried out, via molecular simulation using ab initio...
A Comment on the Letter by H. Hakkinen, R. N. Barnett, and U. Landman, Phys. Rev. Lett. 82, 3264 (1999).Received 30 March 2000DOI:https://doi.org/10.1103/PhysRevLett.85.5250©2000 American Physical Society
We simulate from first principles the energetic, structural, and electronic properties of ferroelectric domains in ultrathin SrRuO_{3}/BaTiO_{3}/SrRuO_{3} capacitors short circuit. The are stabilized down to two unit cells at zero temperature, adopting form a domain closure, common ferromagnetic thin films. closed by in-plane relaxation atoms SrO layer electrode, which behaves more like highly polarizable SrTiO3 than metallic SrRuO3. Even if small, these lateral displacements very important...