Spectroscopy
Orginally a spectrum was what was observed when white light was dispersed through a prism. Soon the term referred to a plot light intensity as a function of frequency or wavelength. Planck later realized that this represents electromagnetic energy.
E = h ν
Today the term has been generalized even further to include any data that are the result of a study where an energy (or frequency) is systematically varied
The recording and studying of spectrum of energy levels in atoms or molecules in the physical sciences is called spectroscopy. A device for recording a spectrum is a spectrometer or spectrophotometer. The latter term is used when an optical spectrum is recorded by the device.
Types of spectroscopy
=Energy of photons
- electromagnetic spectroscopy - The study electomagnetic radiation spectra given off or absorbed by atoms or molecules changing energy levels.
- infra-red spectroscopy - The study of spectra showing infra-red radiation absorbed by atoms or molecules making them vibrate.
- UV/VIS spectroscopy
- Mossbauer spectroscopy - Measures the absorption of gamma-rays by atoms bound in a solid as a function of gamma-ray energy.
- Nuclear magnetic resonance - Measures the resonant absorption of RF radiation by nuclei in a strong magnetic field. Absorption peaks correspond to transitions in the nuclear spin states of the nuclei.
- Raman spectroscopy The study of spectra caused by the scattering and change in frequency of light due to the transition between vibrational/rotational energy levels in molecules.
- Electron spin resonance spectroscopy
- Stark spectroscopy
- Circular Dichroism
- Magnetic Circular Dichroism
kinetic energy of electrons
- X-ray photoelectron spectroscopy
- Electron energy loss spectroscopy
- Auger electron spectroscopy - The analysis of the energies of the stimulated emission of Auger electrons
kinetic energy of ions or molecules
- mass spectrometry - The study of the mass of molecules or atoms, measured by how much they bend as they are exposed to a magnetic field
vibrational energy
Other Topics
- Fourier transform spectroscopy - An efficient method for collecting various spectra. Frequently applied to infra-red spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy.
- See also: spectroscopic analysis