Grant: Research Tools and Instruments

<p>Electron Paramagnetic Resonance (EPR) is an instrumental technique that obtains spectral signatures from species with unpaired electrons. In a strong magnetic field, energy levels for unpaired electrons split into two distinct levels due to the Zeeman effect. Unpaired electrons strongly interact with microwaves under the influence of a magnetic field to transition between the two levels. Due to the Maxwell-Boltzmann distribution of electron energies, the lower state is more populated than the upper state and a net absorption of microwave radiation results. At specific values of the swept magnetic field, resonant absorption of microwave energy takes place, which enables quantification of the Lande <em>g</em>-factor(s) of unpaired electrons in the sample.</p> <br /> <p>&nbsp;The <em>g</em>-factor is characteristic of the orbital in the atom or molecule in which the unpaired electron resides, and <em>g</em> is also a sensitive probe of the environment of the unpaired electron and hyperfine interactions with the nuclear magnetic moment. EPR spectroscopy is the gold standard for studying free radical intermediates, the local environment around transition metal ions, defects in semiconductors, charge carrier traps, oxygen vacancies and select rare earth ions. This makes EPR vital for research in multiple areas such as catalysis, photocatalysis, solar cells, quantum dot luminescence, electronic sensors, redox chemistry of biomolecules, photopolymerization, etc. </p> <br /> <p>The community of researchers at the UofA working in the aforementioned research areas are currently hamstrung by the insufficient availability of high end EPR instrumentation in and around the Edmonton region. &nbsp;Although there is at present one EPR system on the UofA campus dedicated to free radical analysis in the Department of Pharmaceutical Sciences, our focus on photo-activated processes (which require illumination by photons of different wavelengths), variety in sample type (solid, liquid and gas) and routine ""bench-top"" characterization demand a different instrument for applications in semiconductors, sensing and spintronics. Consequently, UofA researchers currently travel to the Structural Sciences Center at the University of Saskatchewan to collect EPR spectra on their samples for publications. There is a severe need for an EPR instrument that is not overcommitted and which is not reserved for the activities of one research group. A second concern is the necessity of simplified data collection and analysis to meet the needs of a large body of new, relatively inexperienced users who nevertheless wish to obtain useful insights from EPR. To balance the needs of both types of researchers, we seek to acquire a newly introduced model of a bench-top EPR spectrometers that is very simple to use and maintain, but is nevertheless highly sensitive and well-equipped to meet the needs of advanced users.</p>