Video Experimental Relacionado
Updated: Jul 6, 2026
08:30
Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
La conductividad eléctrica de la posperovskita en la capa D' de la Tierra
Kenji Ohta1, Suzue Onoda, Kei Hirose
1Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8551, Japan.
Science (New York, N.Y.)
|April 5, 2008
Resumen
La fase posterior a la perovskita en la capa D' de la Tierra exhibe una alta conductividad eléctrica, que influye en el intercambio de momento angular entre el núcleo y el manto. Esto podría explicar las variaciones decenales en la velocidad de rotación de la Tierra.
Área de la Ciencia:
- La geofísica es la geofísica.
- Física de los minerales Física de los minerales
- Ciencias de la Tierra Sólida Ciencias de la Tierra Sólida
Sus antecedentes:
- El manto más bajo de la Tierra (capa D ') exhibe propiedades físicas distintas en comparación con el manto superpuesto debido a una transición de fase reciente de perovskita a post-perovskita.
- Comprender la conductividad eléctrica de esta capa es crucial para explicar los fenómenos geofísicos.
Objetivo del estudio:
- Para investigar la conductividad eléctrica de (Mg0.9Fe0.1) SiO3 después de la perovskita en condiciones relevantes para la capa D'.
- Evaluar las implicaciones de las propiedades eléctricas post-perovskita en la dinámica del límite núcleo-manto de la Tierra y la rotación.
Principales métodos:
- Determinación experimental de la conductividad eléctrica de (Mg0.9Fe0.1) SiO3 después de la perovskita.
- Las mediciones realizadas en condiciones de alta presión y alta temperatura simulan la capa D'.
Principales resultados:
- La conductividad eléctrica de (Mg0.9Fe0.1) SiO3 después de la perovskita es mayor que 10(2) siemens por metro.
- La conductividad muestra una variación mínima con la temperatura en condiciones de capa D''.
- Una capa posterior a la perovskita mejora el acoplamiento electromagnético entre el núcleo fluido y el manto sólido.
Conclusiones:
- La alta y estable conductividad eléctrica de la posperovskita en la capa D' facilita el intercambio de momento angular, lo que podría explicar los cambios decenales observados en la longitud del día en la Tierra.
- Es probable que las variaciones laterales en la conductividad de la capa D'' estén impulsadas por la heterogeneidad química en lugar de las fluctuaciones de temperatura.
Videos de Conceptos Relacionados
01:30The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
01:13Electrical Conductivity
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
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,...
01:28Debye–Huckel–Onsager Conductance Equation
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect. According to this equation,...
01:22Semiconductors
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
01:29Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...