Paramagnetic Character in Thin Films of Metal-Free Organic Magnets Deposited on TiO2(110) Single Crystals

Metal-free organic magnets are a class of emerging materials interesting for their potential use in electronics. We investigate the paramagnetic character of thin films of a pyrene derivative of the nitronyl nitroxide radical deposited on rutile TiO2(110) single crystals. By using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, we find that the paramagnetic character is kept going from "molecule to material". In particular, we evidence the transitions related to the singly occupied molecular orbital, as expected in open shell materials, by using NEXAFS spectroscopy.