Solid solutions of heterospin molecular magnets

Metal complexes with stable radicals form a continuous series of solid solu tions NixCo1-xL2(CH3OH)(2), NixCo1-x L-2(C2H5OH)(2), and NixCo1-xL2(HO(CH2) (4)OH), where L is a deprotonated enaminoketone derivative of 3-imidazoline nitroxide. Variation of x does not affect the structural parameters of lay ered polymeric NixCo1-xL2(CH3OH)(2) and NixCo1-xL2(C2H5OH)(2) and framework NixCo1-xL2(HO(CH2)(4)OH) but leads to smooth variation of the magnetic tra nsition temperature and effective magnetic moment. Spontaneous magnetizatio n is anomalous in the range x similar to 0.8-0.9, where it tends to zero be cause the spontaneous magnetic moment of the 'nickel sublattice' is compens ated by the spontaneous moment of the 'cobalt sublattice'. (C) 2001 Elsevie r Science Ltd. All rights reserved.