Ultra-broadband EPR spectroscopy in field and frequency domains

Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials. We present the first combined terahertz (THz) field and frequency domain electron paramagnetic resonance (HFEPR/FDMR) spectrometer designed to investigate the electronic structure and magnetic properties of molecular systems, thin films and solid state materials in a very broad frequency range of 85-1100 GHz. In this paper, we show high resolution frequency-field (Zeeman) maps (170-380 GHz by 0-15 T) recorded on two single-molecule magnets, [Mn 2 (saltmen) 2 (ReO 4 ) 2 ] and [Mn 2 (salpn) 2 (H 2 O) 2 ](ClO 4 ) 2 , which give direct access to the field-dependence of the energy level diagram. Furthermore, supression of standing waves in the described system and the sensitivity in field and frequency domain operations is evaluated and discussed. Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials.