Electron Paramagnetic Resonance

Electron Paramagnetic Resonance (EPR), also called Electron Spin Resonance (ESR), is a spectroscopic technique that detects and characterizes unpaired electrons in molecules and materials. Discovered by Zavoiskii in 1945, EPR measures the absorption of microwave radiation by paramagnetic species in a magnetic field, providing information about electron spin states, local electronic environment, and molecular dynamics.