A Very-Low-Cost Flexible Electron Spin Resonance Spectrometer for Molecular Nanomagnet Experiments*

Electron spin resonance (ESR) spectroscopy is a useful tool for exploring and manipulating a wide variety of systems, including molecular nanomagnets. Commercial spectrometers offer high sensitivity in specific frequency bands, but are both expensive and limited in their experimental flexibility. We have developed an ESR spectrometer based on a cheap and readily-available field-programmable gate array (FPGA), which, when combined with loop-gap resonators (LGRs), enables spectroscopy on a budget at a wide range of frequencies. I will present the spectrometer design along with benchmark results demonstrating its sensitivity and flexibility with two different combinations of cryostat and magnet, and discuss future experiments on molecular nanomagnets.