Video Experimental Relacionado
Updated: Jun 26, 2026
09:48
Simultaneous Synthesis of Single-walled Carbon Nanotubes and Graphene in a Magnetically-enhanced Arc Plasma
Published on: February 2, 2012
Magnetismo de los átomos de C en las nanoestructuras de BN: implicaciones para los nanodispositivos funcionales
1Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China.
Journal of the American Chemical Society
|January 22, 2009
Resumen
Los átomos de carbono inducen el magnetismo en los nanotubos de nitruro de boro (BNNT) y las láminas. Este magnetismo surge de estados localizados de electrones sp, creando un momento magnético estable de 2.0 μB por átomo, crucial para los nuevos nanodispositivos.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Los nanotubos de nitruro de boro (BNNT) y las láminas hexagonales de nitruro de boro (h-BN) son nanomateriales prometedores.
- La inducción del magnetismo en estos materiales es clave para las aplicaciones espintrónicas.
Objetivo del estudio:
- Investigar la inducción del magnetismo por átomos de carbono en BNNTs y hojas BN.
- Comprender el mecanismo del magnetismo y su potencial para la fabricación de nanodispositivos.
Principales métodos:
- Se emplearon cálculos funcionales de densidad polarizada por espín.
- Se realizó un análisis de la hibridación orbital y la estructura electrónica.
- Se evaluaron las barreras de difusión y las energías de adsorción.
Principales resultados:
- Los átomos de carbono inducen un magnetismo estable en las BNNT y las láminas BN.
- Se observó un momento magnético local de 2,0 μB por átomo de carbono, independientemente del sustrato.
- Dos electrones de valencia de carbono contribuyen a la unión, mientras que dos electrones confinados causan la polarización de espín.
Conclusiones:
- Los átomos de carbono son efectivos para inducir el magnetismo en las nanoestructuras de nitruro de boro.
- Los hallazgos proponen un método de fabricación para nanodispositivos funcionales basados en BN-C.
- Estos resultados allanan el camino para la creación de bloques de construcción virtuales para dispositivos electrónicos avanzados.
Videos de Conceptos Relacionados
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.
01:26Diamagnetism
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
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...
01:14Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
01:23Magnetic Moment of an Electron
Electrons revolving around a nucleus are analogous to a circular current carrying loop. This current produces a magnetic dipole moment proportional to the electron's orbital angular momentum. Since the orbital angular momentum is quantized in terms of the reduced Planck's constant, the dipole moment is quantized in the Bohr Magneton. The value of the Bohr magneton is 9.27 x 10-24 Am2. Electrons also have an intrinsic spin angular momentum, and the associated spin magnetic moment is...
01:30Paramagnetism
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...