Search research articles

ACERCA DE JoVE

Visión General Liderazgo Blog Centro de Ayuda JoVE

AUTORES

Proceso de Publicación Consejo Editorial Alcance y Políticas Revisión por Pares Preguntas Frecuentes Enviar

BIBLIOTECARIOS

Testimonios Suscripciones Acceso Recursos Consejo Asesor de Bibliotecas Preguntas Frecuentes

INVESTIGACIÓN

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archivo

EDUCACIÓN

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Centro de Recursos para Profesores Sitio de Profesores

Términos y Condiciones de Uso

Política de Privacidad

Videos de Conceptos Relacionados

Valence Bond Theory

Valence 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...

Atomic Nuclei: Magnetic Resonance

Atomic Nuclei: Magnetic Resonance

The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...

Atomic Nuclei: Nuclear Relaxation Processes

Atomic Nuclei: Nuclear Relaxation Processes

In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...

Diamagnetism

Diamagnetism

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.

Ferromagnetism

Ferromagnetism

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...

Metal-Semiconductor Junctions

Metal-Semiconductor Junctions

The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The semiconductor's...

También podría leer

Artículos Relacionados

Artículos vinculados a este trabajo por autores compartidos, revista y gráfico de citas.

Ordenar por

Same author

Ultra-long-range spin coupling in graphene revealed by atomically resolved spin excitations.

Nature communications·2026

Same author

Engineered Protein-Based Ionic Conductors for Sustainable Energy Storage Applications.

Advanced materials (Deerfield Beach, Fla.)·2025

Same author

Strain Engineering of Correlated Charge-Ordered Phases in 1T-TaS<sub>2</sub>.

Nano letters·2025

Same author

Electrically tunable quantum interference of atomic spins on surfaces.

Nature communications·2025

Same author

On-chip single-crystal plasmonic optoelectronics for efficient hot carrier collection and photovoltage detection.

Light, science & applications·2025

Same author

The Next 25 Years of Nanoscience and Nanotechnology: A <i>Nano Letters</i> Roadmap.

Nano letters·2025

Search research articles

Video Experimental Relacionado

Updated: May 10, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

El efecto Kondo en los contactos atómicos ferromagnéticos.

M Reyes Calvo¹, Joaquín Fernández-Rossier, Juan José Palacios

¹Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Alicante, San Vicente del Raspeig, E-03790 Alicante, Spain.

|May 2, 2009

Resumen

Los contactos a escala atómica de hierro, cobalto y níquel exhiben inesperadamente la física de Kondo. Este fenómeno, impulsado por las interacciones de electrones a nanoescala, revela una nueva comprensión de las nanoestructuras magnéticas.

Más Videos Relacionados

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Published on: July 20, 2022

Videos de Experimentos Relacionados

Last Updated: May 10, 2026

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Published on: June 7, 2018

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe₁₊_YTe Using a Spin-polarized Scanning Tunneling Microscope

Published on: March 24, 2019

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Published on: July 20, 2022

Área de la Ciencia:

Física de la materia condensada Física de la materia condensada
Ciencia de los materiales Ciencia de los materiales.
Nanotecnología La nanotecnología es la nanotecnología.

Sus antecedentes:

Los metales ferromagnéticos arquetípicos como el hierro, el cobalto y el níquel exhiben propiedades electrónicas y magnéticas masivas distintas.
Las interacciones superficiales y a nanoescala pueden alterar el comportamiento electrónico y magnético observado en los materiales a granel.

Objetivo del estudio:

Investigar el transporte electrónico en contactos a escala atómica de ferromagnetos puros.
Proporcionar evidencia directa de las modificaciones a nanoescala de las propiedades magnéticas.

Principales métodos:

Fabricación y caracterización eléctrica de contactos a escala atómica de hierro, cobalto y níquel.
Análisis de las características de conductividad para identificar fenómenos de transporte electrónico.
Cálculos teóricos para apoyar las observaciones experimentales.

Principales resultados:

Los contactos ferromagnéticos a escala atómica mostraron inesperadamente la física de Kondo, caracterizada por la detección de momentos magnéticos locales.
Se observó una resonancia Fano-Kondo en la conductancia, consistente con la teoría de Kondo.
Se encontraron distribuciones log-normales dependientes del material del ancho de resonancia, que varían con la temperatura.

Conclusiones:

Los cambios de coordinación a nanoescala modifican significativamente el magnetismo en los materiales ferromagnéticos.
Las correlaciones electrónicas y la geometría a escala atómica son cruciales para comprender las nanoestructuras magnéticas.
El estudio revela la física de Kondo en ferromagnetos a nanoescala, desafiando las suposiciones de materiales a granel.