Doping effect of nonmagnetic impurity on the spin-Peierls-like transition in the quasi-one-dimensional (quasi-1D) spin system of 1-(4 '-nitrobenzyl)pyridinium bis(maleonitriledithiolato)nickelate

摘要

A nonmagnetic compound, [NO(2)BzPy][Cu(mnt)(2)] (mnt(2-) = maleonitriledithiolate; NO(2)BzPy(+)=1-(4'-nitrobenzyl)pyridinium), is isostructural with [NO(2)BzPy][Ni(mnt)(2)], which is a quasi-1D spin system and exhibits a spin-Peierls-like transition with J = 192 K in the gapless state and spin energy gap = 738 K in the dimerization state, respectively. Further, five nonmagnetic impurity doped compounds [NO(2)BzPy][CuxNi1-x(mnt)(2)] (x = 0.04-0.74) were prepared, and their crystal structures as well as magnetic properties were investigated. The nonmagnetic doping causes the suppression of the spin transition with an average rate of 139(13) K/percentage of dopant concentration, and the transition collapse is estimated at around x > 0.5.