Fig. 2: The EPR spectra and magnetic susceptibility data of the PVEO radical polymer.

a The first derivative EPR spectra of 2 and PVEO dissolved in chloroform collected at room temperature and at the microwave frequency of 9.8 GHz. b The typical Lorentzian g-factor plot for PVEO. c The doubly integrated EPR spectra of TEMPO-OH standard, alkyne-substituted verdazyl (2)  and PVEO. By comparing their EPR signals with the TEMPO-OH standard, the radical content of 2 is determined to be 97%, while PVEO shows the radical content of 88%. d The magnetic susceptibility χ_m curve from 2 K ≤ T ≤ 300 K with an applied field of 0.1 T, fit to the Curie–Weiss Law with fit shown as black curve, demonstrating paramagnetic behavior. The fit is corrected with the diamagnetic susceptibility which is calculated using Pascal’s correction. The 1/χ_m curve plotted on right axis shows a clear dependence of susceptibility with temperature where susceptibility decreases at higher temperatures. e Moment vs. field curve from 2 K ≤ T ≤ 20 K, fitted to the paramagnetic Brillouin function for S = 1 and S = ½. f Electrical conductivity of PVEO in NiFe/PVEO/Pd device structure, displaying weak temperature dependence. The inset shows the linear I–V curve, indicating Ohmic conduction in PVEO. The data points represent the average value for four different devices and the error bars represent the standard deviation from this average.