Hallilmiö

Hallilmiö is a Finnish term that roughly translates to "hall phenomenon" or "hall effect." It refers to a set of observable phenomena that occur in conductors or semiconductors when they are subjected to a magnetic field while an electric current is flowing through them. The most prominent of these phenomena is the Hall voltage, which is a potential difference that develops across the conductor perpendicular to both the direction of the current and the direction of the magnetic field.

This effect arises because the moving charge carriers within the conductor, when subjected to the Lorentz force from the magnetic field, are deflected to one side. This deflection leads to an accumulation of charge on the sides of the conductor, creating an electric field that opposes further deflection. The equilibrium between the magnetic force and the electric force results in the measurable Hall voltage.

The magnitude and polarity of the Hall voltage are dependent on the material's properties, specifically the type of charge carriers (electrons or holes) and their density. By measuring the Hall voltage, it is possible to determine important characteristics of the material, such as the sign of the charge carriers and their concentration. This makes the Hall effect a valuable tool in solid-state physics and materials science for characterizing semiconductors and other conductive materials. It has numerous applications, including magnetic field sensors, current sensors, and integrated circuits.