Publications (40)
Meta-screening and permanence of polar distortion in metallized ferroelectrics
Hong Jian Zhao, Alessio Filippetti, Carlos Escorihuela-Sayalero +5
Ferroelectric materials are characterized by a spontaneous polar distortion. The behavior of such distortions in the presence of free charge is the key to the physics of metallized…
On the nature of the melting line of bcc sodium
Eduardo R. Hernandez, Jorge Iniguez
Recent experiments have obtained the melting line of sodium up to pressures of about 130 GPa, finding that the melting line from the {\em bcc} phase reaches a maximum at a temperat…
Novel magnetoelectric effects via penta-linear interactions
Hong Jian Zhao, M. N. Grisolia, Yurong Yang +4
Magnetoelectric multiferroic materials, particularly with the perovskite structure, are receiving a lot of attention because of their inherent coupling between electrical polarizat…
A First-Principles Approach to Insulators in Finite Electric Fields
Ivo Souza, Jorge Iniguez, David Vanderbilt
We describe a method for computing the response of an insulator to a static, homogeneous electric field. It consists of iteratively minimizing an electric enthalpy functional expre…
Understanding the Unique Structural and Electronic Properties of SrFeO2
J. M. Pruneda, Jorge Iniguez, Enric Canadell +2
We report a first-principles study of SrFeO, an infinite-layer oxide with Fe atoms in a perfect square-planar coordination down to essentially 0 K. Our results reveal this stri…
Ferroelectricity at ferroelectric domain walls
Jacek C. Wojdel, Jorge Iniguez
We present a first-principles study of model domain walls (DWs) in prototypic ferroelectric PbTiO3. At high temperature the DW structure is somewhat trivial, with atoms occupying h…
Analysis of soft optical modes in hexagonal BaTiO3: transference of perovskite local distortions
Jorge Iniguez, Alberto Garcia, J. M. Perez-Mato
We have performed detailed first-principles calculations to determine the eigenvectors of the zone-center modes of hexagonal BaTiO3 and shown that the experimentally relevant low-e…
Quantitative analysis of the first-principles effective-Hamiltonian approach to ferroelectric perovskites
Silvia Tinte, Jorge Iniguez, Karin M. Rabe +1
The various approximations used in the construction of a first-principles effective Hamiltonian for BaTiO3, and their effects on the calculated transition temperatures, are discuss…
Energetics of oxygen-octahedra rotations in perovskite oxides from first principles
Peng Chen, Mathieu N. Grisolia, Hong Jian Zhao +5
We use first-principles methods to study oxygen-octahedra rotations in ABO3 perovskite oxides. We focus on the short-period, perfectly antiphase or in-phase, tilt patterns that cha…
Magnetoelectric response of multiferroic BiFeO3 and related materials
Jacek C. Wojdel, Jorge Iniguez
We present a first-principles scheme for computing the magnetoelectric response of multiferroics. We apply our method to BiFeO3 (BFO) and related compounds in which Fe is substitut…
Tuning the atomic and domain structure of epitaxial films of multiferroic BiFeO3
C. J. M. Daumont, S. Farokhipoor, A. Ferri +4
Recent works have shown that the domain walls of room-temperature multiferroic BiFeO3 (BFO) thin films can display distinct and promising functionalities. It is thus important to u…
First-principles study of the temperature-pressure phase diagram of BaTiO3
Jorge Iniguez, D. Vanderbilt
We investigate the temperature-pressure phase diagram of BaTiO_3 using a first-principles effective-Hamiltonian approach. We find that the zero-point motion of the ions affects the…
Effective-Hamiltonian modeling of external pressures in ferroelectric perovskites
Jorge Iniguez, J. B. Neaton, D. Vanderbilt
The phase-transition sequence of a ferroelectric perovskite such as BaTiO_3 can be simulated by computing the statistical mechanics of a first-principles derived effective Hamilton…
Ab initio study of proper topological ferroelectricity in layered perovskite La2Ti2O7
Jorge Lopez-Perez, Jorge Iniguez
We present a first-principles investigation of ferroelectricity in layered perovskite oxide La2Ti2O7 (LTO), one of the compounds with highest Curie temperature known (1770 K). Our…
Giant Direct and Inverse Electrocaloric Effects in Multiferroic Thin Films
Claudio Cazorla, Jorge Iniguez
Refrigeration systems based on compression of greenhouse gases are environmentally threatening and cannot be scaled down to on-chip dimensions. In the vicinity of a phase transitio…
Amorphization induced by pressure: results for zeolites and general implications
Inmaculada Peral, Jorge Iniguez
We report an {\sl ab initio} study of pressure-induced amorphization (PIA) in zeolites, which are model systems for this phenomenon. We confirm the occurrence of low-density amorph…
Multi-phonon scattering and Ti-induced hydrogen dynamics in sodium alanate
Jorge Iniguez, T. Yildirim, T. J. Udovic +3
We use ab initio methods and neutron inelastic scattering (NIS) to study the structure, energetics, and dynamics of pure and Ti-doped sodium alanate (NaAlH_4), focusing on the poss…
Pressure-induced structural, electronic, and magnetic effects in BiFeO3
O. E. Gonzalez-Vazquez, Jorge Iniguez
We present a first-principles study of multiferroic BiFeO3 at high pressures. Our work reveals the main structural (change in Bi's coordination and loss of ferroelectricity), elect…
Optimized local modes for lattice dynamical applications
Jorge Iniguez, Alberto Garcia, J. M. Perez-Mato
We present a new scheme for the construction of highly localized lattice Wannier functions. The approach is based on a heuristic criterion for localization and takes the symmetry c…
Ultrafast switching of the electric polarization and magnetic chirality in BiFeO3 by an electric field
Satadeep Bhattacharjee, Dovran Rahmedov, Dawei Wang +2
Using a first-principles-based effective Hamiltonians within molecular dynamics simulations, we discover that applying an electric field that is opposite to the initial direction o…
Theoretical investigation of hydrogen storage in metal-intercalated graphitic materials
Manuel Cobian, Jorge Iniguez
We have used first-principles methods to investigate how metal atoms dispersed in the interlayer space of graphitic materials affect their hydrogen-binding properties. We have cons…
First-principles study of the multi-mode anti-ferroelectric transition of PbZrO3
Jorge Iniguez, Massimiliano Stengel, Sergey Prosandeev +1
We have studied ab initio the phase transition in PbZrO3, a perovskite oxide usually presented as the prototypic anti-ferroelectric material. Our work reveals the crucial role that…
First-principles study of (BiScO3){1-x}-(PbTiO3){x} piezoelectric alloys
Jorge Iniguez, David Vanderbilt, L. Bellaiche
We report a first-principles study of a class of (BiScO3)_{1-x}-(PbTiO3)_x (BS-PT) alloys recently proposed by Eitel et al. as promising materials for piezoelectric actuator applic…
Ab-initio design of perovskite alloys with predetermined properties: The case of Pb(Sc_{0.5} Nb_{0.5})O_{3}
Jorge Iniguez, L. Bellaiche
A first-principles derived approach is combined with the inverse Monte Carlo technique to determine the atomic orderings leading to prefixed properties in Pb(Sc_{0.5}Nb_{0.5})O_{3}…
Manipulating chiral-spin transport with ferroelectric polarization
Xiaoxi Huang, Xianzhe Chen, Yuhang Li +28
A collective excitation of the spin structure in a magnetic insulator can transmit spin-angular momentum with negligible dissipation. This quantum of a spin wave, introduced more t…
First-principles study of Ti-doped sodium alanate surfaces
Jorge Iniguez, Taner Yildirim
We have performed first-principles calculations of thick slabs of Ti-doped sodium alanate (NaAlH_4), which allows to study the system energetics as the dopant progresses from the s…
Flat branches and pressure amorphization
Morrel H. Cohen, Jorge Iniguez, J. B. Neaton
After summarizing the phenomenology of pressure amorphization (PA), we present a theory of PA based on the notion that one or more branches of the phonon spectrum soften and flatte…
A 2D ferroelectric vortex lattice in twisted BaTiO3 freestanding layers
Gabriel Sanchez-Santolino, Victor. Rouco, Sergio. Puebla +10
The wealth of complex polar topologies recently found in nanoscale ferroelectrics result from a delicate balance between the materials intrinsic tendency to develop a homogeneous p…
First-Principles Study Of The Structural Instabilities In Hexagonal Barium Titanate: Coupling Between The Soft Optical And The Acoustic Modes
Jorge Iniguez, Alberto Garcia, J. M. Perez-Mato
Hexagonal BaTiO_3 undergoes a structural phase transition to an orthorhombic C222_1 phase at T_0 = 222 K. The transition is driven by a soft optical mode with E_2u symmetry whose c…
Electric control of the magnetization in BiFeO/LaFeO superlattices
Zeila Zanolli, Jacek C. Wojdel, Jorge Iniguez +1
First-principles techniques are used to investigate the behavior of BiFeO/LaFeO perovskite oxide superlattices epitaxially grown on a (001)-SrTiO substrate. The cal…
Structurally Triggered Metal-Insulator Transition in Rare-Earth Nickelates
Alain Mercy, Jordan Bieder, Jorge Iniguez +1
Rare-earth nickelates form an intriguing series of correlated perovskite oxides. Apart from LaNiO3, they exhibit on cooling a sharp metal-insulator electronic phase transition, a c…
Multiple structural transitions driven by spin-phonon couplings in a perovskite oxide
Claudio Cazorla, Oswaldo Dieguez, Jorge Iniguez
Spin-phonon interactions are central to many interesting phenomena, ranging from superconductivity to magnetoelectric effects. Yet, they are believed to have a negligible influence…
Unusual structural tuning of magnetism in cuprate perovskites
Jorge Iniguez, Taner Yildirim
Understanding the structural underpinnings of magnetism is of great fundamental and practical interest. Se_{1-x}Te_{x}CuO_{3} alloys are model systems for the study of this questio…
First-principles approach to lattice-mediated magnetoelectric effects
Jorge Iniguez
We present a first-principles scheme for the computation of the magnetoelectric response of magnetic insulators. The method focuses on the lattice-mediated part of the magnetic res…
A three-order-parameter bistable magnetoelectric multiferroic metal
Andrea Urru, Francesco Ricci, Alessio Filippetti +2
Using first-principles calculations we predict that the layered-perovskite metal BiMnO is a ferromagnet, ferroelectric, and ferrotoroid which may realize the long so…
Dynamics of Berry-phase polarization in time-dependent electric fields
Ivo Souza, Jorge Iniguez, David Vanderbilt
We consider the flow of polarization current J(t)=dP/dt produced by a homogeneous electric field E(t) or by rapidly varying some other parameter in the Hamiltonian of a solid. For…
Effects of Vacancies on Properties of Relaxor Ferroelectrics: a First-Principles Study
L. Bellaiche, Jorge Iniguez, Eric Cockayne +1
A first-principles-based model is developed to investigate the influence of lead vacancies on the properties of relaxor ferroelectric Pb(Sc1/2Nb1/2)O3 (PSN). Lead vacancies generat…
Devonshire-Landau free energy of BaTiO3 from first principles
Jorge Iniguez, S. Ivantchev, J. M. Perez-Mato +1
We have studied the Devonshire-Landau potential underlying the phase transition sequence of BaTiO3 using the first-principles effective Hamiltonian of Zhong, Vanderbilt, and Rabe […
Ti-enhanced kinetics of hydrogen absorption and desorption on NaAlH4 surfaces
Jorge Iniguez, Taner Yildirim
We report a first-principles study of the energetics of hydrogen absorption and desorption (i.e. H-vacancy formation) on pure and Ti-doped sodium alanate (NaAlH4) surfaces. We find…
Effects of atomic short-range order on the properties of perovskite alloys in their morphotropic phase boundary
A. M. George, Jorge Iniguez, L. Bellaiche
The effects of atomic short-range order on the properties of Pb(Zr_{1-x}Ti_x)O_3 alloy in its morphotropic phase boundary (MPB) are predicted by combining first-principles-based me…