Advisory Panel Jonathan W. Amy Jack W Frazer G Phillip Hicks
Donald R Johnson Charles E . Klopfenstein Marvin Margoshes
Harry L Pardue Ralph E Thiers William F Ulrich
The Hall Effect Devices and Applications E. D. SISSON’ F. W. Bell, Inc., 4949 Freeway Dr., East Columbus, Ohio 43229
Modern semiconductor technology has produced Hall effect devices capable of very accurately measuring magnetic field flux densities and gradients. Applications of the Hall effect include field monitoring in spectrometers, beam deflection coils, cyclotron or linear accelerator magnets, and magnetic resonance measurements.
in semiconductor technolhave produced ;in nmazing variety of new devices. Transistors, diodes, silicon-controlled rectifiers, and many more component,s obtain their >.pecial properties as a result of “junctions”-regions where diasiiiiilar materials :ire joined together. The electrical properties of the junctions determine tlie device characteristics. A snialler class of clevices utilize only the properties of the bulk semiconductor material ituelf, a n d have no junctions. The Hall effect device is nn esnmple in which the galvanomagnetic properties of the material provide n sensitive electrical response to an applied magnetic field. DYAKCES
A ogy
Background
Discovery of the Hall effect’ is attributed to Dr. Edwin H. Hall, who, in 1 8 i 9 , made the first esperimentnl demonstration of the action of a magnetic field upon the current flowing in a conductor. He showed that the field acted directly on the current, tending to crowd the charges to one side of the conductor, and that a measurable potential, therefore, was generated across the conductor width. Using strips of gold foil, Hall determined that the voltage developed across the strip was proportional to the current’ flowing and to the magnetic field strength, as shown in Equation 1:
V H = kIcB Sew affiliation to he announced.
(1)
where V , is the Hall voltage, X: is a const:iiit of proportionality, I , is the strip ciirrent, and B is the magnetic field >trength. Hall published his work in the American Journal of Mathenlatics in 1879 in :I pnper entitled “On a S e w riction of the 1I:ignet on E!ectric Ciirrents.” The angle at wliicli the mngnetic flus l i n c intersect the Hnll plnte iiffccted the Hall voltage siicli that only the component of field perpendiciilar to the plate was effective. Tlius, the espres.
