Electron paramagnetic resonance
Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the spins excited are those of the electrons instead of the atomic nuclei. EPR spectroscopy is particularly useful for studying metal complexes and organic radicals. EPR was first observed in Kazan State University by Soviet physicist Yevgeny Zavoisky in 1944, and was developed independently at the same time by Brebis Bleaney at the University of Oxford.
Typical set-up for recording EPR spectra. The user would be seated next to the RF generator, magnet, and controls for sample temperature.
This low-temperature ESR-STM in the Center for Quantum Nanoscience is one of the first STMs globally to measure electron spin resonance on single atoms.
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum.
An example of spectroscopy: a prism analyses white light by dispersing it into its component colors.
A huge diffraction grating at the heart of the ultra-precise ESPRESSO spectrograph.
UVES is a high-resolution spectrograph on the Very Large Telescope.
Atomic spectra comparison table, from "Spektroskopische Methoden der analytischen Chemie" (1922).
