Video Experimental Relacionado
Updated: Aug 26, 2025
07:03
Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
8.9K
Cristales multiferoicos de BINOL axial-chiral con coexistencia de ferroelectricidad y ferroelasticidad
Yu-Ling Zeng1, Yong Ai1, Shu-Yu Tang1
1Ordered Matter Science Research Center, Nanchang University, Nanchang330031, People's Republic of China.
Journal of the American Chemical Society
|October 12, 2022
Resumen
Los investigadores desarrollaron nuevos cristales multiferroicos axial-quirales utilizando BINOL. Estos materiales de alta temperatura demuestran propiedades ferroeléctricas y ferroelásticas, allanando el camino para nuevos diseños moleculares multiferroicos.
Área de la Ciencia:
- Ciencias de los materiales
- Física del estado sólido
- La cristalografía
Sus antecedentes:
- La quiralidad, una propiedad fundamental que se encuentra en la naturaleza y la física, es crucial en la ciencia de los materiales.
- La quiralidad de punto se establece en el diseño de ferroeléctricos moleculares.
- Sin embargo, la quiralidad axial sigue siendo poco explorada para el diseño de materiales ferroeléctricos.
Objetivo del estudio:
- Diseñar y sintetizar nuevos cristales multiferroicos axial-quirales.
- Investigar las propiedades ferroeléctricas y ferroelásticas de estos nuevos materiales.
- Para explorar el papel de la quiralidad axial en multiferroicos de alta temperatura.
Principales métodos:
- Síntesis de compuestos orgánicos de silicio basados en el BINOL axial-quiral ((R) BINOL-DIPASi y (S) BINOL-DIPASi).
- Caracterización mediante microscopía de fuerza piezoeléctrica (PFM) para la observación del dominio ferroeléctrico.
- Los bucles de histeresis de voltaje de polarización (P-V) para confirmar la ferroelectricidad y la conmutación de dominio.
- Microscopía de luz polarizada (PLM) para visualizar la evolución del dominio ferroelástico.
Principales resultados:
- Diseño y síntesis exitosas de (R) -BINOL-DIPASi y (S) -BINOL-DIPASi, los primeros cristales multiferroicos axial-quirales de alta temperatura.
- Observación de una transición de fase ferroeléctrica/ferroelástica completa del tipo 2F1 a altas temperaturas (362 K y 363 K).
- Demostración de la conmutación del dominio ferroeléctrico a través de bucles PFM y P-V, y visualización de dominios ferroelásticos en forma de franja utilizando PLM.
Conclusiones:
- La quiralidad axial, ejemplificada por el bloque de construcción BINOL, induce efectivamente la estructura polar y la ferroelectricidad en los materiales moleculares.
- El componente orgánico de silicio mejora la barrera de energía de rotación, lo que lleva a altas temperaturas de transición de fase.
- Este estudio establece una estrategia eficiente para el diseño de multiferroicos moleculares mediante la incorporación de la quiralidad axial, abriendo nuevas vías en el descubrimiento de materiales.
Más Videos Relacionados
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
8.2K
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.6K
Videos de Conceptos Relacionados
01:31Ferromagnetism
2.4K
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...
2.4K
02:25Molecules with Multiple Chiral Centers
12.0K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
12.0K
03:02Colors and Magnetism
12.2K
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...
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...
12.2K
02:25Chirality
24.9K
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
24.9K
02:52Stereoisomerism
12.3K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
12.3K
02:42Valence Bond Theory
9.1K
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...
9.1K