Electron Spin Resonance (english version)___

(update February 24th 2023

Person in charge

Olivier CHAUVET - Etienne JANOD

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Topic

EPR (Electronic Paramagnetic Resonance) is a spectroscopic technique that allows the detection of species with unpaired electrons, via their magnetic signature.These species present in solid or liquid materials can be free radicals in molecular or biological materials, paramagnetic ions of transition metals such as Cu(II), Mn(II), V(IV), Fe(III),Cr(III), Cr(V), Co(II), Rh(II), Ni(I), Mo(V) or Ti(III), paramagnetic defects, spins of conduction electrons… .This technique allows obtaining chemical information (nature and environment of the paramagnetic species).It can also provide insight into the physical or physico-chemical properties of compounds: electronic properties of conductors or insulators, magnetic properties, redox properties, etc.

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Equipments

Electron Spin Resonance (continuous wave, Bruker Elexsys E 500)

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Performances

• • • samples :
      -Type: powder, crystal, gel, thick films, mass between a few tens of µg and a few tens of mg,
      - dimensions : the sample should fit into a tube of about 2-3 mm inside diameter
    • available cavities:
      - X-Band: resonance field around 3350 G for g = 2
      - Q-Band: resonance field around 12500 G pour g = 2
    • Sensitivity: under the most favorable conditions, detection threshold close to one part per billion (1 ppb),
    • Temperature range: :from 77 to 400K (liquid nitrogen cryostat)
    • Possibilities (tuning required) to make measurements under light irradiation, in an electrochemical cell, under electrical bias,...
      

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Application examples

The applications of EPR cover many fields of scientific research, in chemistry, physics, materials science, biology and medicine.Among the recent examples obtained on the IMN spectrometer, we can note measurements aimed at characterizing defects induced by irradiation in materials used in the field of health.

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Learn more:

Links towards Bruker E500 user manual