Definition of electron paramagnetic resonance
Electron paramagnetic resonance is a kind of magnetic resonance technology originated from the magnetic moment of unpaired electrons. It can be used to qualitatively and quantitatively detect unpaired electrons contained in a substance atom or molecule, and explore the structural characteristics of its surrounding environment. For free radicals, the orbital magnetic moment has almost no effect, and most of the contribution of the total magnetic moment comes from the electron spin, so electron paramagnetic resonance is also called "electron spin resonance."