Magnetic properties of the d-metal heavy-fermion system Li1-xZnxV2O4

We have studied the magnetic relaxation rate of Li1-xZnxV2O4 by means of qu asielastic neutron scattering. At low temperatures, LiV2O4 shows the typica l features of a canonical heavy-fermion state, namely a residual quasielast ic line width of 0.5 meV and a square root temperature dependence. However, at elevated temperatures, LiV2O4 behaves like a weak ferromagnetic d-metal . Zn doping leads to a lattice expansion and drives the system via a spin g lass state to an antiferromagnetically ordered state in pure ZnV2O4. For lo w Zn concentrations, a similar behavior of the magnetic relaxation rate is observed as in pure LiV2O4. A slight increase of the residual line width an d a strong decrease of the intensity is observed upon increasing Zn concent ration. The results indicate the increasing freezing-out of magnetic fluctu ations due to the formation of a spin-glass state at low temperatures. (C) 2000 Elsevier Science B.V. All rights reserved.