A5088664903- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Multiferroics and related materials
- Quantum and electron transport phenomena
- Magnetism in coordination complexes
- Magnetic properties of thin films
- Iron oxide chemistry and applications
- Ferroelectric and Piezoelectric Materials
- Magnetic Properties and Applications
- Magnetic Properties and Synthesis of Ferrites
- Seismic Imaging and Inversion Techniques
- Geomagnetism and Paleomagnetism Studies
- Hydraulic Fracturing and Reservoir Analysis
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Organic and Molecular Conductors Research
- Magnetic Properties of Alloys
- Quantum many-body systems
- Metallic Glasses and Amorphous Alloys
- Clay minerals and soil interactions
- Model-Driven Software Engineering Techniques
- Advanced Database Systems and Queries
- Magneto-Optical Properties and Applications
- Drilling and Well Engineering
Federico Santa María Technical University
2013-2025
Massachusetts Institute of Technology
2009-2022
The University of Texas at Dallas
2022
IIT@MIT
2012
Universidad de Antioquia
2005-2007
Stanford University
2001-2002
Manipulation of spontaneous polarization through sliding, stacking, and twisting in multilayer like hBN.
It is known that the spin-chain compound Ca3Co2O6 exhibits very interesting plateaus in magnetization as a function of magnetic field at low temperatures. The origin them still controversial. In this paper we study thermal behavior with single-flip Monte Carlo simulation on triangular lattice and demonstrate decisive influence metastable states splitting ferrimagnetic 1/3 plateau below 10 K. We consider [Co2O6]n chains giant moments described by large Ising spins planar clusters open...
Linear asymmetrical magnetoimpedance (MI) has been obtained in thin multilayer strips of exchange-coupled FeNi(5 nm)/IrMn(15 nm)/FeNi(40 nm)/Cu(100 nm)/FeNi(5 nm), which the MI response is enhanced by including a Cu layer between two 40 nm NiFe layers. The antiferromagnetic creates an exchange bias that shifts both hysteresis loop and response. peak positions are shifted to higher magnetic field as probe frequency increases. behavior can be tuned around zero external without need for biasing...
We present hybrid density functional calculations suggesting that magnetism in cubic SrTi1−xCoxO3−δ (STCO) with x = 0.25 is sensitive to the nearest neighbor arrangement of Co and presence oxygen vacancies. Spin polarized for which (nn) spacing a, 2a or 3a a lattice parameter predict lowest energies nn separation favor ferromagnetic state. Oxygen deficiency (δ=0.125) lowers average valence state favors mixed spin states (high adjacent vacancy low non-adjacent Co), an increase band gap...
The crystal structure, magnetic anisotropy and magnetoelasticity of epitaxial SrTi(0.87)Fe(0.13)O(3-δ) (STF13) SrTi(0.65)Fe(0.35)O(3-δ) (STF35) films grown on (001), (011), (111) oriented SrTiO(3) substrates were investigated. grew with compressive in-plane strain underwent tetragonal, monoclinic, rhombohedral distortions the substrates, respectively. All samples showed room temperature hysteresis loops strong out-of-plane anisotropy. resulting magnetoelastic was an order magnitude greater...
Multifunctional oxides could provide the basis of many tomorrow's technologies, and understanding physics their oxygen defects is often key to tailoring device performance. The authors study electronic structure, magnetism, magnetooptical properties SrTi${}_{1-x}$Fe${}_{x}$O${}_{3-\ensuremath{\delta}}$, an important ``non-dilute'' magnetic semiconductor, illustrate its application in a nonreciprocal photonic device. This insight into oxygen-vacancy-mediated magnetism will be relevant for...
One-dimensional (1D) magnetic systems offer rich phenomena in the quantum limit, proving more chemically accessible than zero-dimensional or higher-dimensional frameworks. Single-walled carbon nanotubes (SWCNT) have recently been used to encapsulate trimetric nickel(II) acetylacetonate [Nanoscale, 2019, 11, 10615–10621]. Here, we investigate magnetization on spin chains based nickel trimers by Matrix Product State (MPS) simulations. Our findings reveal plateaus exchange/magnetic-field phase...
Monte Carlo modeling suggests that the magnetothermal features of Fe2P-structured FeCrAs-like compound offer a promising route for design magnetocaloric materials. The prototype structure is modeled as antiferromagnetically coupled layered Heisenberg systems mimicking distorted Kagome/triangular stacked architecture FeCrAs iron-pnictide. magnetic entropy change ΔSm(T) presents plateau-like behavior which can be tailored by tuning either JCr−Fe/JCr−Cr exchange energy ratio or field. plateau...
In this work, we report the magnetocaloric effect (MCE) in two systems of non-interactive particles: first corresponds to Landau problem case and second an electron a quantum dot subjected parabolic confinement potential. scenario, realize that is totally different from what happens when degeneracy single confined magnetic field not taken into account. particular, system negligible, cools system, while other case, strong, heats up. For study competition between characteristic frequency...
The asymmetrical magnetoimpedance (MI) response has been analyzed in thin multilayer strips of exchange-coupled [NiFe (t nm)/IrMn (35 nm)] × n(t), where t and n take values 20, 30, 40, 60 nm = 15, 10, 8, 5, respectively. antiferromagnetic layer creates an exchange bias that shifts both the hysteresis loop MI response, magnitude this shift depends on ferromagnetic (FM) thickness. peak positions are also shifted to a higher magnetic field as probe frequency increases, ratio increases with...
Ferroics based on transition-metal (TM) substituted SrTiO$_{3}$ have called much attention as magnetism and/or ferroelectricity can be tuned by using cations substitution and defects, strain oxygen deficiency. C. A. Ross et al. [Phys. Rev. Applied 7, 024006 (2017)] demonstrated the SrTi$_{1-x}$Fe$_{x}$O$_{3-\delta}$ (STF) magnetization behavior for different deposition oxygen-pressures, substrates magnetic fields. The relation between deficiency ferroic orders is yet to well understood,...
In this work, we report the magnetocaloric effect (MCE) in two systems of non-interactive particles, first corresponds to Landau problem case and second, an electron a quantum dot subjected parabolic confinement potential. scenario, realize that is totally different from what happens when degeneration single confined magnetic field not taken into account. particular, degeneracy system negligible, cools system, while other case, strong, heats up. For second study competition between...
We show that a double-twisted ABC trilayer graphene, formed by stacking two trilayers with rotation angle between them, is semiconductor gap of about 30 meV. Importantly, flat bands in the electronic structure are observed even for large angles, and localization electrons follows same pattern as graphene. Our first-principles calculations this behavior holds at least angles from 7 to 21 degrees. further study charge redistribution function angle. Below degrees, escapes rotated layers AA...
This work examines the interplay between thermal observables and entanglement of molecular magnets conformed by antiferromagnetic rings Cr7Ni. We show how in quantification spin-entanglement, quantities such as specific heat CMag magnetocaloric (MCO) provide further insight into description rings. Such reproduce entanglement-map behavior a function external magnetic field temperature. Studying ring 2(Cr7Ni)L-like molecules (L being link) is essential order to understand enhance MCO...
We use density functional theory to calculate the structure, band-gap, and magnetic properties of oxygen-deficient ${\mathrm{SrTi}}_{1\ensuremath{-}x\ensuremath{-}y}{\mathrm{Fe}}_{x}{\mathrm{Co}}_{y}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ with $x=y=0.125$ $\ensuremath{\delta}={0,0.125,0.25}$. The valence high or low spin states Co Fe ions, as well lattice distortion band gap, depend on oxygen deficiency, locations vacancies, direction Fe-Co axis. A charge redistribution that...
Fe(2)P-like structures can be strongly frustrated magnets due to their Kagome/triangular intercalated-layer structure. A complete magnetic solution of the complex spin architecture, and hence full potential phenomena in material prototypes, is yet found. previous model for a representative FeCrAs-like system used mean-field effective-spin describe 3g-Wyckoff located Fe-triangles. Such an approach demonstrated outstanding magnetocaloric properties but left question whether intra-trimer...