the flipping back and forth between two spin directions of electrons in a magnetic field when electromagnetic radiation of the proper frequency is applied.
Abbreviation: ESR.
Also called electron paramagnetic resonance, spin resonance.
British Dictionary definitions for electron spin resonance
electron spin resonance
noun
1.
a technique for investigating paramagnetic substances by subjecting them to high-frequency radiation in a strong magnetic field. Changes in the spin of unpaired electrons cause radiation to be absorbed at certain frequencies ESR See also nuclear magnetic resonance
Abbr. ESR A spectrometric method, based on measurement of the spins of unpaired electrons in a magnetic field, for detecting and estimating free radicals in organic reactions.