Electron Spin Resonance Spectrometer
( ELEXSYS E500 )

Manufactured by Bruker Analytik GmbH

( Photo 22kB )

This spectrometer is used for detecting a physical phenomenon of absorption of electromagnetic radiation in the microwave region by paramagnetic species that are subjected to an external magnetic field. The phenomenon is called Electron Spin Resonance (ESR) or Electron Paramagnetic Resonance (EPR). Paramagnetic species, e.g., free radicals, some metal ions, are those molecules which have a not equal to zero total electron spin and are mostly ESR active. The spectrometer operates with continuous-wave at ca. 9 GHz and over a temperature range from 4.2 K to 300 K. Another main accessory is a Nd:YAG raser irradiation system, which permits time resolved measurements on short-lived radical signals (down to 80 ns). ESR spectroscopy has applications in many fields: chemistry, biology, solid-state physics, paleontology, materials development, and even medicine.

Example applications include:

1. structure of free radicals
2. time-resolved ESR studies on the transient paramagnetic species
3. spin trapping of transient free radicals
4. spin label and spin probe experiments using nitroxide free radicals
5. dynamic processes of the excited states generated by laser excitation
6. ESR studies of paramagnetic transition metals
7. Electronic structure of the short-lived excited triplet states and the excited states of open-shell molecules