Name: hall voltage and charge carriers
Uploaded: 2025-05-22T09:05:51.000Z
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North Carolina K-12 Science Standard Course of Study

9-12

Physical Science

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Motion and Stability- Forces and Interactions

PS.PSc.6.4

The Hall Effect

Stellen Sie sich einen rechteckigen stromdurchflossenen Leiter mit Elektronen als Ladungsträgern vor. Wenn ein Magnetfeld senkrecht zur Ebene des Leiters angelegt wird, driften die Elektronen, die sich in einer geraden Linie bewegen, aufgrund der ablenkenden Magnetkraft.
Die Elektronen sammeln sich auf der einen Seite des Leiters an und hinterlassen überschüssige positive Ladungen auf der anderen Seite. Durch diese Ladungstrennung entsteht im Inneren des Leiters ein elektrisches Feld, das auf jedes Elektron eine elektrische Kraft ausübt, die der magnetischen Kraft entgegenwirkt.
Im Gleichgewicht gleicht die Größe der elektrischen Kraft die magnetische Kraft aus und stoppt ein weiteres Driften der Elektronen. Die Potentialdifferenz zwischen den beiden Seiten des Leiters ist die Hallspannung.
Durch die Angabe der Driftgeschwindigkeit in Form des Stroms kann die Hall-Spannung auch zur Messung der Anzahldichte der Ladungsträger verwendet werden.
Hall-Sonden messen die Größe eines unbekannten Magnetfelds aus der Hall-Spannung und den bekannten Parametern des Leiters.
Eine wichtige Anwendung dieser Entdeckung besteht darin, dass die Polarität der Hall-Spannung impliziert, ob die Ladungsträger im Leiter negativ oder positiv sind.

<ol>
	<li>OpenStax. (2019). Universitätsphysik Vol. 2. [Webversion]. Abgerufen von 514-516 <a href="https://openstax.org/books/university-physics-volume-2/pages/11-6-the-hall-effect">https://openstax.org/books/university-physics-volume-2/pages/11-6-the-hall-effect</a></li>
</ol>

der hall-effekt

Edwin H. Hall entwarf im Jahr 1879 ein Experiment, das verwendet werden konnte, um die Polarität der vorherrschenden Ladungsträger in einem leitenden Material zu identifizieren. Aus historischer Sicht war dieses Experiment das erste, das zeigte, dass die Ladungsträger in den meisten Metallen negativ sind.

<img alt="Figure1" src="/files/ftp_upload/13772/13772_Figure_1.png" style="text-align: center" />

Betrachten Sie eine Metallplatte mit der Breite L in einem konstanten Magnetfeld. Die Elektronen bewegen sich von rechts nach links, sodass die magnetische Kraft, die sie erfahren, die Elektronen zur oberen Kante der Platte drückt. Dadurch entsteht an der oberen Kante der Platte eine überschüssig negative Ladung und an der unteren Kante eine überschüssig positive Ladung, was zu einem elektrischen Feld führt, das von unten nach oben gerichtet ist. Die Ladungskonzentration an beiden Kanten nimmt zu, bis ein Gleichgewichtszustand erreicht ist. Im Gleichgewichtszustand wird die elektrische Kraft auf die Elektronen in einer Richtung durch die entgegengesetzt gerichtete magnetische Kraft ausgeglichen. Diese Situation, in der die elektrischen und magnetischen Felder senkrecht zueinander stehen, wird als "kreuzende-Felder-Situation" bezeichnet.

Der Strom in der Platte I lässt sich durch die Driftgeschwindigkeit vd und den Querschnittsbereich A der Platte ausdrücken. Die Potentialdifferenz zwischen den Kanten des Streifens, die auch als Hall-Spannung bezeichnet wird, ergibt sich aus:

<img alt="Equation1" src="/files/ftp_upload/13772/13772_Equation_1.png" style="text-align: center; height: 40px;" />

Die Polarität der Hall-Spannung zeigt, ob die Ladungsträger positiv oder negativ sind. Eine weitere wichtige Anwendung dieses Effekts besteht für Materialien mit einer bekannten Ladungsträgerdichte. Die gemessene Hall-Spannung kann den Wert eines unbekannten Magnetfeldes liefern. In Forschungslabors, in denen die Felder der für präzise Messungen verwendeten Elektromagneten sehr stabil sein müssen, wird häufig eine "Hall-Sonde" als Teil des elektronischen Schaltkreises verwendet, um das Feld zu regeln.

Der Hall-Effekt

Edwin H. Hall entwickelte im Jahr 1879 ein Experiment, mit dem die Polarität der vorherrschenden Ladungsträger in einem leitenden Ladungsträger bestimmt werden konnte.

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Unit 1

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Magnetic Forces and Fields

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KEY TERMS AND CONCEPTS

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hall voltage and charge carriers

Hall voltage and charge carriers are explained through Edwin H. Hall’s 1879 experiment. His setup helped identify the polarity of the main charge carriers in a conducting material. It also showed, for the first time, that the charge carriers in most metals are negative.

A metal slab is placed in a constant magnetic field. The electrons move from right to left, so the magnetic force pushes them toward the top edge of the slab. This leaves excess negative charge at the top and excess positive charge at the bottom. As a result, an electric field forms from the bottom edge to the top edge.

The charge buildup continues until equilibrium is reached. At that point, the electric force on the electrons balances the magnetic force in the opposite direction. This is called a crossed-field situation because the electric and magnetic fields are perpendicular to each other. The current in the slab, I, can be written in terms of the drift velocity, v d, and the cross-sectional area, A.

The potential difference between the two edges is called the Hall voltage. Its polarity reveals whether the charge carriers are positive or negative. When the density of charge carriers is known, the Hall voltage can also be used to find an unknown magnetic field. In research labs, a Hall probe is often used in electronic circuits to help regulate electromagnet fields so they stay steady for precise measurements.

Hall Voltage and Charge Carriers

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Hall voltage and charge carriers are explained through Edwin H. Hall’s 1879 experiment. His setup helped identify the polarity of the main charge carriers in a conducting material. It also showed, for the first time, that the charge carriers in most metals are negative. A metal slab is placed in a constant magnetic field. The electrons move from right to left, so the magnetic force pushes them toward the top edge of the slab. This leaves excess negative charge at the top and excess positive...

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Learn how Hall voltage forms in a magnetic field, how it reveals charge carrier polarity, and how Hall probes help measure and control magnetic fields.

Hall Voltage and Charge Carriers | JoVE K12

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Hall Voltage and Charge Carriers

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