Muon-spin-rotation and magnetization study of metal-organic magnets based on the dicyanamide anion

We report the results of a study of the metal-organic magnets M-II[N(CN)(2) ](2), where M-II = Ni, Co and Mn, using bulk magnetization and muon-spin re laxation (mu SR), Implanted muons are sensitive to the onset of long-range magnetic order in each of these materials and strong muon-spin relaxation i s observed in the paramagnetic state due to low-frequency fluctuations of t he electronic moments in the 10(9)-10(10) Hz range. The size of the muon-sp in relaxation in the paramagnetic state can be related to the magnitude of the transition-metal-ion moment. Very strongly damped oscillations are obse rved below the magnetic transition temperature in Co[N(CN)(2)](2).