Doping effect of magnetic impurities on the spin–Peierls compound p-CyDOV

The magnetic susceptibilities of mixed verdazyl radical crystals, (p-CyDOV)1−x(p-CyDTV)x (x=0∼0.07), were measured to study the effects of magnetic impurities (p-CyDTV) on the spin–Peierls (SP) transition of p-CyDOV radical crystal, where the >CO group in p-CyDOV is replaced by the >CS group in p-CyDTV. The SP transition temperature (TSP=15 K) reduces rapidly upon p-CyDTV doping and the SP state disappears around x=0.03. The effect of p-CyDTV substitution was not observed in the X-ray diffraction pattern of the mixed-radical crystals (x=0∼0.07).