Electron Spin Resonance of Defects in Spin Chains— o-(DMTTF)2X: A Versatile System Behaving Like Molecular Magnet

International audienceThe paper presents the Electron Paramagnetic Resonance study of defects in the spin chain o-(DMTTF)2X family using continuous wave and pulsed techniques. The defects in spin chains are strongly correlated and present similar microscopic structure as a molecular magnet. By means of 2D-HYSCORE and DFT calculations we show a strong reduction of hyperfine coupling between the defects and the nuclear spin bath. We assume that the reduction is due to the Heisenberg exchange interaction which screens the effect of the nuclei