Magnetic property of verdazyl radical alloy, (p-CDpOV)(1-x) (p-BDpOV)(x). Doping effect of magnetic impurities on quasi-one dimensional Heisenberg organic ferromagnet (p-CDpOV) and antiferromagnet (p-BDpOV) with S=1/2

The magnetic susceptiblities, ESR and powder X-ray patterns of verdazyl rad ical alloy, (p-CDpOV)(1-x)(p-BDpOV)(x) (x = 0-1), were measured to study th e doping effects of magnetic impurities for the quasi-1D Heisenberg ferroma gnet (p-CDpOV) and antiferromagnet (p-BDpOV) with S = 1/2, which have simil ar van der Waals radius to each other. The susceptibility curves systematic ally change with impurity concentration x. The most noticeable point is tha t the impurity effect is rather mild on the 1D ferromagnetic Heisenberg sys tem. The characteristic feature of 1D ferromagnet still survives even in th e heavily doped sample with x = 0.50. The positive Weiss constant (theta) a nd the ferromagnetic intrachain exchange interaction (2J(intrachain)) remai n constant between x = 0 and 0.50. The results indicate that the p-BDpOV ra dical functions as an ideal dopant for the 1D ferromagnet; p-CDpOV. This is the first report of the effects of magnetic impurities on the quasi-1D fer romagnetic chain system.