Related Experiment Video
Updated: Jun 13, 2026
07:03
Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
Hybrid functional study of proper and improper multiferroics.
1Consiglio Nazionale delle Ricerche - Superconducting and Innovative Devices (CNR-SPIN), 67100 L' Aquila, Italy. astroppa@aquila.infn.it
Physical Chemistry Chemical Physics : PCCP
|May 7, 2010
Summary
The Heyd-Scuseria-Ernzerhof (HSE) hybrid functional accurately predicts multiferroic properties, outperforming simpler density functional theory (DFT) methods. HSE is crucial for realistic simulations of multiferroic materials, but its effects vary by compound.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Chemistry
Background:
- Multiferroic (MF) materials exhibit coupled ferroelectric and magnetic orders, offering potential for advanced electronic devices.
- Accurate theoretical prediction of MF properties is challenging due to complex electronic structures.
Purpose of the Study:
- To investigate the efficacy of the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional for describing multiferroic properties.
- To compare HSE calculations with experimental data and other theoretical methods like GW and Perdew-Burke-Ernzerhof (PBE).
- To assess the necessity of beyond-local/semilocal DFT approximations for multiferroics.
Main Methods:
- Density Functional Theory (DFT) calculations using the HSE hybrid functional.
- Comparative analysis with experimental results and GW calculations.
- Investigation of prototypical proper (BiFeO3) and improper (orthorhombic HoMnO3) multiferroic systems.
Main Results:
- HSE provides accurate predictions for structural, electronic, magnetic, and ferroelectric properties of multiferroics.
- HSE is a reliable tool for predictive first-principles investigations of multiferroic systems.
- Electric polarization in magnetically-induced ferroelectrics (HoMnO3) decreases significantly with HSE compared to PBE, while it slightly increases for proper ferroelectrics (BiFeO3).
Conclusions:
- Effects beyond local and semilocal DFT are essential for realistic multiferroic descriptions.
- No universal trend exists for HSE corrections; each multiferroic compound requires specific investigation.
- HSE formalism emerges as an accurate and predictive tool for multiferroic research.
More Related Videos
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
Related Concept Videos
01:31Ferromagnetism
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:29Imperfections in Crystal Structure: Non-Stoichiometric Defects
Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...
01:28Types Of Superconductors
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
01:17Theory of Metallic Conduction
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...