Millimetre-wave studies on single crystals of the organic radical 2-benzimidazolyl nitronyl nitroxide

We report temperature dependent millimetre-wave spectroscopic experiments on single crystals of the organic molecular magnet 2-benzimidazolyl nitronyl nitroxide, in the range 1.4–100 K. This organic radical shows quasi one-dimensional (1-d) ferromagnetic intermolecular interactions with the intrachain exchange coupling constant J/kB = +22 K and interchain coupling constant J′/kB = 0.24 K. The linewidth of the electron spin resonance at low temperatures was seen to be considerably broadened as compared to that at higher temperatures. This is consistent with the low dimensional behaviour of the linewidth predicted theoretically. We also see a shift in resonance field at low temperatures. We also present the results of angular dependence experiments carried out at temperatures of 1.4 and 50 K, and frequency dependence experiments at 1.4 and 50 K.

Graphical abstractTemperature dependent, angle dependent and frequency dependent millimetre wave spectroscopic studies on single crystals of the organic molecular magnet 2-benzimidazolyl nitronyl nitroxide have been reviewed. The linewidths and resonance fields of the electron spin resonance spectra at low temperatures were particularly observed in detail.Figure optionsDownload full-size imageDownload as PowerPoint slide