Name: hall voltage and charge carriers
Uploaded: 2025-05-22T09:05:51.000Z
Duration: 1 min 30 s
Channel: JoVE

K12 Standards

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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

Рассмотрим прямоугольный токонесущий проводник с электронами в качестве носителей заряда. Когда магнитное поле прикладывается перпендикулярно плоскости проводника, электроны, движущиеся по прямой линии, дрейфуют из-за отклоняющей магнитной силы.
Электроны накапливаются на одной стороне проводника, оставляя избыточные положительные заряды на другой стороне. Это разделение зарядов создает электрическое поле внутри проводника, которое оказывает электрическое воздействие на каждый электрон, противодействующий магнитной силе.
В равновесном состоянии величина электрической силы уравновешивает магнитную силу, останавливая дальнейший дрейф электронов. Разность потенциалов между двумя сторонами проводника и есть напряжение Холла.
Выражая скорость дрейфа в терминах тока, напряжение Холла также может быть использовано для измерения плотности чисел носителей заряда.
Зонды Холла измеряют величину неизвестного магнитного поля по напряжению Холла и известным параметрам проводника.
Важным применением этого открытия является то, что полярность напряжения Холла подразумевает, являются ли носители заряда в проводнике отрицательными или положительными.

<ol>
	<li>OpenStax. (2019). Университетская физика Том 2. [Веб-версия]. Получено из 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>

Эффект Холла

Эдвин Х. Холл в 1879 году разработал эксперимент, который можно использовать для определения полярности основных носителей заряда в проводящем материале. С исторической точки зрения, этот эксперимент первым показал, что основными носителями заряда в большинстве металлов являются отрицательно заряженные электроны.

<img alt="Figure1" src="/files/ftp_upload/13772/13772_Figure_1.png" style="text-align: center" />

Рассмотрим металлическую пластину шириной L в постоянном магнитном поле. Электроны движутся справа налево, поэтому магнитная сила, которую они испытывают, отталкивает электроны к верхнему краю пластины. При этом на верхнем краю возникает избыток отрицательного заряда, а на нижнем краю - избыток положительного заряда, что приводит к возникновению электрического поля, направленного снизу вверх. Концентрация заряда на обоих краях увеличивается до установления равновесного состояния. В равновесии электрическая сила на электроны в одном направлении уравновешивается магнитной силой в противоположном направлении. Такая ситуация, при которой электрическое и магнитное поля перпендикулярны друг другу, называется перекрёстным полем.

Ток в пластине I можно записать через скорость дрейфа vd и поперечное сечение пластины A. Разность потенциалов между краями полосы, которую также называют Холловским напряжением, рассчитывается по формуле:

<img alt="Equation1" src="/files/ftp_upload/13772/13772_Equation_1.png" style="text-align: center; height: 40px;" />

Полярность Холловского напряжения показывает, являются ли носители заряда положительными или отрицательными. Ещё одним важным применением этого эффекта является для материалов с известной плотностью носителей заряда. Измеренное Холловское напряжение может дать значение неизвестного магнитного поля. В исследовательских лабораториях, где необходимо иметь стабильные электромагнитные поля для точных измерений, часто используется "Холловский зонд" как часть электронной схемы для регулирования поля.

В 1879 году Эдвин Х. Холл разработал эксперимент, который можно было использовать для определения полярности преобладающих носителей заряда в проводящем ...

Education

JoVE Core

Physics

Физика

Unit 1

Раздел 1

Magnetic Forces and Fields

Магнитные силы и поля

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

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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the hall effect

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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key terms and concepts

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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JoVE Core Physics introduces the theory and application of fundamental physics topics, including kinematics, dynamics, fluid mechanics, statics, waves, and acoustics, with concise and easy-to-understand animated videos. Additionally, the scientist-in-action videos demonstrate the application of related concepts in classical and original research experiments performed in today's laboratories worldwide.

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Hall Voltage and Charge Carriers

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