Magnetoresistance Glossary

Colossal Magnetoresistance
"Colossal" magnetoresistance is caused by metal-insulator transitions driven by a magnetic field. The change in resistance is proportional to the square of the magnetic field. The model for "Large" magnetoresistance in this study is not yet known; moreo ver the change in resistance is linearly related to the magnetic field.
doping
The addition of impurities to a semiconductor for the purpose of modifying its electrical conductivity; in this study it is hoped that doping with various elements (i.e. Ni) will increase the magnetoresistance.
gauss
Unit of magnetic induction corresponding to the magnetic flux density that will induce an electromotive force of one abvolt (108 volt) in each linear centimeter of a wire moving laterally at one cm per second at right angles to a magnetic flux. One gauss corresponds to 104 tesla (T).
Giant Magnetoresistance
In "Giant" magnetoresistance, the magnetic-field response of interfacial spins modulates electron transport. The change in resistance is proportional to the square of the magnetic field. The model for "Large" magnetoresistance in this study is not yet k nown; moreover the change in resistance is linearly related to the magnetic field.
Magnetic Field
Region in the neighborhood of a magnet, electric current, or changing electrical field, in which magnetic forces are observable. Magnetic fields force moving, electrically charged particles in a circular or helical path.
Neutron and X-Ray Diffraction
A phenomenon in which the atoms of a crystal, by virtue of their uniform spacing, cause an intereference pattern of the waves present in an incident beam of x-rays or neutrons. The atomic planes of the crystal act on the X-rays or neutrons in exactly the same manner as does a uniformly-ruled grating on a beam of light. These techniques are used to describe molecular structures.
quenching
Rapid cooling of a metal object from the high temperature at which it has been shaped. This usually is undertaken to maintain mechanical properties associated with a crystalline structure or phase distribution that would be lost upon slow cooling. In th is experiment liquid nitrogen was used for quenching.

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