|electron spin resonance|
|See also nuclear magnetic resonance ESR 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|
electron spin resonance n.
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.