Physics
Electron Spin Resonance (ESR)
Quick fact
ESR is so sensitive that it can detect a single unpaired electron in a sample of billions of atoms, making it a premier tool for studying radicals and defects.
Why this is interesting
You've probably heard of MRI scans, which use the spin of atomic nuclei. But did you know that the spin of electrons can also be harnessed—using microwave radiation—to reveal the presence of free radicals and study the magnetic properties of materials?