The magnetic susceptibilities (chi(M)) of diluted p-CyDOV radical crystals
(p-CyDOV)(1 - x)(p-CyDOV-H)(x) (x = 0-0.10), were measured to study the eff
ects of nonmagnetic impurities, p-CyDOV-H (amine precursor of p-CyDOV), on
the spin-Peierls (SP) transition of p-CyDOV radical crystal. The SP transit
ion temperature (T-SP = 15 K) decreased rapidly with increasing x and the S
P state disappeared around x = 0.07. The chi(M) of diluted radical crystal
with x = 0.01-0.05 below Ts, can be explained by the sum of the susceptibil
ities of the spin-Peierls state (chi(SP)), antiferromagnet (chi(AFM)), and
Curie impurity (chi(Curic)). (C) 2000 Elsevier Science B.V. All rights rese
rved.