A5048179155- Graphene research and applications
- Molecular Junctions and Nanostructures
- Quantum and electron transport phenomena
- Luminescence Properties of Advanced Materials
- Magnetic properties of thin films
- Advanced Chemical Physics Studies
- Advancements in Battery Materials
- Magnetic and transport properties of perovskites and related materials
- Perovskite Materials and Applications
- Hydrogen Storage and Materials
- Fullerene Chemistry and Applications
- 2D Materials and Applications
- Topological Materials and Phenomena
- Surface Chemistry and Catalysis
- Physics of Superconductivity and Magnetism
- Inorganic Chemistry and Materials
- Boron and Carbon Nanomaterials Research
- Nuclear materials and radiation effects
- Crystallization and Solubility Studies
- Crystal Structures and Properties
- Rare-earth and actinide compounds
- Advanced Battery Materials and Technologies
- Catalytic Processes in Materials Science
- Carbon Nanotubes in Composites
- Solid-state spectroscopy and crystallography
Universidad de Oviedo
2016-2024
Nanomaterials and Nanotechnology Research Center
2019-2024
University of Fribourg
2013-2015
Universidad de Valladolid
2008-2015
Fribourg Development Agency
2014-2015
Technical University of Denmark
2009
Abstract Red‐emitting narrow‐band phosphors are of utmost importance for next‐generation white‐light phosphor‐converted light‐emitting diodes (pc‐wLEDs) improved efficacy and optimized correlated color temperatures. A promising representative crystallizing in an ordered variant the UCr 4 C structure type is Sr[Li 2 Al O N ]:Eu 2+ (SALON:Eu ) emitting at a desirable wavelength 614 nm. Despite expected eightfold coordination Eu ions by four 3− 2− ions, respectively, exact local symmetry 1:1...
We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. investigate the stability and decomposition alloys containing 1 alkali atom, Li, Na, or K (M(1)); alkali, alkaline earth 3d/4d transition atom (M(2)) plus two to five (BH(4))(-) groups, i.e., M(1)M(2)(BH(4))(2-5), using number model structures with trigonal, tetrahedral, octahedral, free coordination borohydride complexes. Of over 700 investigated...
The precise determination of dose-effect curves and the combination effect drugs is crucial importance in development new therapies for most dreadful diseases. We have found that current implementations theory Chou et al. are not accurate enough some circumstances might lead to erroneous predictions synergistic or antagonistic behaviour. identified source inaccuracies fixed it thereby improving accuracy those methods. Here we explain main features our approach demonstrate its higher as...
We present a density-functional comparative study of the electronic properties and structural trends late isoelectronic $3d$ (Fe, Co, Ni) $4d$ (Ru, Rh, Pd) free-standing transition metal clusters 13 23 atoms. Different types structures have been analyzed: compact arrangements such as icosahedral shape, open cubic ones, reminiscent crystal lattices. calculated total-energy differences between spin isomers, well charge spin-moment distribution within clusters. found that some correlate with...
We report a density-functional-theoretic study of the stability and electronic structure two recently proposed borophene sheets with Pmmn symmetry nonzero thickness. then investigate nanoribbons (BNRs) derived from these nanostructures, particular attention to technologically relevant properties like magnetism transport. consider perpendicular directions for edges stripes as well different lateral widths. show that Pmmn8 sheet, 8 atoms in its unit cell generated by interpenetrating lattices,...
A new blue emitting Eu<sup>2+</sup> phosphor with ultra high thermal stability for CRI near-UV LEDs.
Spin-crossover (SCO) switching of individual molecules connected to graphene electrodes is detected in the electrical current.
A theoretical study of hydrogen deposition and insertion in bimetallic Pd–Pt nanoalloys has been carried out the framework density functional theory. Our model systems are 147-atom clusters cuboctahedral shape stoichiometries Pd1.00, Pd0.91Pt0.09, Pd0.82Pt0.18, Pd0.54Pt0.46, resembling those recently produced characterized context H (Kobayashi, H. et al. J. Am. Chem. Soc.2010, 132, 5576.). Adsorption absorption energies have computed for all stable positions different compositions....
Abstract Eu 2+ ‐activated phosphors of the UCr 4 C structure type have emerged as promising new (ultra‐)narrow band phosphors. Especially ‐type alkali lithosilicates caused a sensation in field phosphor research recent years due to their consistent (ultra)narrow‐band luminescence cyan and green range that can pave way novel backlighting LEDs with high color gamut. The compound “K 2 Na [Li 3 SiO ] :Eu ” stands out strikingly narrow emission (<0.2 eV or <30 nm full width at half maximum...
Recently, graphene triangulene chains have been synthesized, and their magnetic response has analyzed by scanning tunneling microscopy methods Mishra et al. [Nature (London) 598, 287 (2021)]. Motivated this study, we determine the exchange bilinear biquadratic constants of calculating two-spin rotations in spirit force theorem. We then analyze open-ended, odd-numbered chains, whose edge states pair up forming a triplet ground state. propose three experimental approaches that enable us to...
A ligand field density functional theory model for two-open-shell f and d electrons.
Spin-crossover (SCO) active iron(II) complexes are an integral class of switchable and bistable molecular materials. Spin-state switching properties the SCO have been studied in bulk single-molecule levels to progress toward fabricating molecule-based memory elements. Supramolecular featuring anchoring groups for metallic electrodes, example, gold (Au), ideal candidates study spin-state at level. In this study, we report on characteristics supramolecular 1 2 composed functional...
Here we report a theoretical analysis of the luminescence properties Sr2Si5N8 host lattices codoped with Ca(2+) and Eu(2+). These systems have been first synthesized by Li et al. [J. Solid State Chem., 2008, 181, 515], who found that doping provokes red-shifting emission peak Eu(2+), from 620 nm to 643 nm. However, mechanism drives this shift is still unclear experimental data. Based on density functional theory ligand field analysis, study structure, stability, Eu(2+) embedded in...
Finite-length armchair graphene nanoribbons can behave as one dimensional topological materials, that may show edge states in their zigzag-terminated edges, depending on width and termination. We here a full solution of Tight-Binding rectangles any length be seen either finite-length or zigzag ribbons. find exact analytical expressions for both bulk eigen-states eigen-energies. write down the Coulomb interactions among introduce Hubbard-dimer model to analyse emergence features different...
We propose a method to determine the magnetic exchange interaction and onsite anisotropy tensors of extended Heisenberg spin models from density functional theory including relativistic effects. The is based on Liechtenstein-Katsnelson-Antropov-Gubanov torque formalism, whereby energy variations upon infinitesimal rotations are performed. assume that Kohn-Sham Hamiltonian expanded in nonorthogonal basis set pseudoatomic orbitals. define local operators both Hermitian satisfy relevant sum...
We present a systematic theoretical study of the electronic transport in hydrogen passivated zigzag graphene and silicene nanoribbons with between zero four neighboring H atoms on one edge replaced by magnetic transition metals (Fe, Co, Ni). The calculations were performed using equilibrium density-functional theory generalized gradient approximation to exchange correlation. considered moments two edges aligned both ferromagnetically (Ferro-F form) antiferromagnetically (Ferro-A form)....
In this work we have analyzed in detail the magnetic anisotropy a series of hydrotris(pyrazolyl)borate (Tp(-)) metal complexes, namely [VTpCl](+), [CrTpCl](+), [MnTpCl](+), [FeTpCl], [CoTpCl], and [NiTpCl], their substituted methyl tert-butyl analogues with goal observing effect ligand field on properties. [NiTpCl] arises as consequence out-of-state spin-orbit coupling, covalent changes induced by substitution hydrogen atoms pyrazolyl rings does not lead to drastic anisotropy. On other hand,...
Abstract LiK 7 [Li 3 SiO 4 ] 8 :Eu 2+ (LKLSO:Eu ) was synthesized by a high‐temperature solid‐state reaction. It is accessible from K 2 CO , Li O, and an Eu‐source (Eu O conventional reaction in nickel crucibles under constant flow of forming gas. The crystal structure LKLSO has been determined single‐crystal X‐ray diffraction it crystallizes the tetragonal space group I (no. 88) with lattice parameters =1560.83(5), c =1278.23(4) pm, volume V =0.31140(2) nm . compound isostructural to NaK...
A systematic ab initio study of the structures and magnetic properties ${\text{Mo}}_{4\ensuremath{-}x}{\text{Fe}}_{x}$ clusters $(x=1--3)$ is reported. The linear structure ${\text{Mo}}_{4}$ remains stable upon substitutional doping by one even two Fe atoms, above which a transition to tetrahedral geometry pure ${\text{Fe}}_{4}$ takes place. cluster ${\text{Mo}}_{2}{\text{Fe}}_{2}$ particularly interesting since, among rich variety isomers different dimensionalities orders, its ground state...
Monatomic chains of molybdenum encapsulated in single-walled carbon nanotubes (CNTs) different chiralities are investigated using density functional theory. We determine the optimal size CNT for encapsulating a single atomic wire, as well most stable arrangement adopted by wire. also study transport properties ballistic regime computing transmission coefficients and tracing them back to electronic conduction channels wire host. predict that CNTs appropriate radii Mo have metallic behavior,...
We report a theoretical density functional theory study of the absorption and adsorption hydrogen in Pd core/Pt shell cubo-octahedral nanoparticles 55 147 atoms. have explored all possible sites available for loading. The relative stability H different is calculated discussed terms local geometrical chemical environments. As general trend, most stable are pyramidal interstices at interface offering volume around $2\ifmmode\times\else\texttimes\fi{}2.60$ \AA{}${}^{3}$, with moderate atomic...
We use density functional theory to analyze the charge transfer between lithium or magnesium cations and a graphene wall beyond predictions of classical Marcus theory. To that end, metal atoms are placed in three different kinds environments: (i) vacuum, (ii) among fluorine simulate molten salt, (iii) an ionic liquid. prove complete electrodes takes place all studied environments process starts at longer distances from electrode Vertical ionization potentials vertical electron affinities...