Members: Tzippora Weglein, Michael Malka

Supervisor: Prof. Amir Capua

Free radicals are atoms or molecules with an unpaired electron in an atomic orbital. Sensing free radicals is important for identifying chemical interactions. Traditionally, this is done using an electron spin resonance (ESR) system. Typical ESR systems are large, expensive, and difficult to operate. Recently, the Spintronics Lab has developed the Ferris Ferromagnetic Resonance (FMR) technique for measuring spin currents in spintronic electronic devices. The Ferris FMR is based on large-amplitude modulation of the magnetic field, thus allowing sensitive measurements. Here, we developed the Ferris ESR method which benefits from enhanced sensitivity as compared to the Ferris FMR, making it suitable for sensing free radicals. To this end, we designed a new magnetic field waveform generator that provides a rectangular magnetic field which improves the measured signal. We also replaced the stripline waveguide of the Ferris FMR with antennas, allowing us to flood the sample with radiation and elicit a greater reaction. The result is a table-top system that is cost-efficient, wideband, and simple to operate. Our approach, applying concepts from the field of electrical engineering, will make the ESR accessible to almost any chemical lab both in academia and industry.