X-band benchtop electron paramagnetic resonance/electron spin resonance (EPR or ESR) spectroscopy
Based on its high sensitivity and stability, EPR200M offers an economical, low-maintenance, and user-friendly experience for EPR study and analysis.
The design integrates the optimized microwave, magnetic field, probe, and central control module, making the EPR machine easier to transport, space-saving, and adaptable to a broader range of test environments.
Sweeping ranges: -100 to 6500 Gauss, with over-zero field scanning possible.
Magnetic field: air-cooled and compact.
Magnetic field scanning control tech: uniformity of better than 50 mG in the sample area, guaranteeing high-quality spectra.
Ultra-low noise microwave generation technology, combined with high-quality microwave probes and weak signal detection, guarantees the high sensitivity of the EPR spectrometer.
Experienced technical and application engineers provide professional services to help customers master the EPR analysis and attribution of EPR spectra, even for beginners.
EPR Application Cases
EPR Detection of Free Radicals
Free radicals are atoms or groups with unpaired electrons that are formed when a compound molecule is subjected to external conditions such as light or heat and the covalent bonds are split. For more stable free radicals, EPR can detect them directly and quickly. For short-lived free radicals, they can be detected by spin trapping. For example, hydroxyl radicals, superoxide radicals, single-linear oxygen light radicals, and other radicals produced by photocatalytic processes.
Paramagnetic Metal lons
For transition metal ions (including iron, palladium, and platinum group ions with unfilled 3d, 4d, and 5d shell respectively) and rare earth metal ions (with unfilled 4f shell), these paramagnetic metal ions can be detected by EPR spectrometer due to the presence of the single electrons in their atomic orbitals, thus obtaining the valence and structure information. In the case of transition metal ions, there are usually multiple valence states and spin states with high and low spins. Parallel modes in a two-mode cavity allow detection of the integer spin regime.
Conduction Electrons in Metal
The EPR line shape that conducts electrons is related to the size of the conductor, which is of great significance in the field of lithium-ion batteries. EPR can non-invasively probe the interior of the battery to study the deposition process of lithium in a close-to-real situation, from which the microscopic size of metallic lithium deposits can be inferred.
Material Doping And Defects
Metallofullerenes, as new nanomagnetic materials, have significant application value in magnetic resonance imaging, single-molecule magnets, spin quantum information, and other fields. Through EPR technology, the electron spin distribution in metallofullerenes can be obtained, providing an in-depth understanding of the ultrafine interaction between spin and the magnetic nucleus of metals. It can detect changes in spin and magnetism of metallofullerenes in different environments. (Nanoscale 2018, 10, 3291)
Photocatalysis
Semiconductor photocatalytic materials have become a hot research topic due to their potential applications in environmental, energy, selective organic transformation, medical, and other fields. EPR technology can detect active species generated on the surface of photocatalysts, such as e-, h+, •OH, O2, 1O2, SO3, etc. It can detect and quantify vacancies or defects in photocatalytic materials, assist in studying active sites and reaction mechanisms of photocatalytic materials, optimize parameters for subsequent photocatalytic application processes, detect active species and their proportions during photocatalysis, and provide direct evidence for system reaction mechanisms. The figure shows the EPR spectra of 0.3-NCCN and CN, indicating that 0.3-NCCN contains more unpaired electrons, higher crystallinity, and an extended p-conjugated system, resulting in better photocatalytic performance. (International Journal of Hydrogen Energy, 2022, 47: 11841-11852)
Parallel magnetic field signal of a diamond |
Signal of TEMPOL after deaeration |
Various free radical signals |
Cu valence |
CIQTEK Electron Paramagnetic Resonance EPR Spectroscopy Collections |
An Introduction to CIQTEK Benchtop EPR Spectroscopy EPR200M |
CIQTEK EPR Spectroscopy User Stories by Cornell University Researchers |
Analysis of Free Radical Spectra in Cigarettes with the CIQTEK EPR Spectrometer |
CIQTEK self-developed EPR-Pro is based on the Windows system, with a wide variety of EPR experiments, compatible with various experimental modes such as continuous wave, pulse, and two-dimensional experiments, it can achieve automated tuning, angle control, temperature control, etc., and generate experimental reports with one click. The data processing software can be used offline, with rich data processing functions, including quantitative EPR analysis.