Eur. Phys. J. B 25, 289-298 (2002)
https://doi.org/10.1140/epjb/e20020033

Ground-state properties of LiV₂O₄ and Li_1-xZn_x(V_1-yTi_y)₂O₄

¹ Experimentalphysik V, Elektronische Korrelationen und Magnetismus, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
² Experimentalphysik III, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
³ Experimentalphysik II, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany

Corresponding author: ^a manuel.brando@physik.uni-augsburg.de

Received: 16 March 2001
Revised: 30 October 2001
Published online: 15 February 2002

Abstract

We present susceptibility, microwave resistivity, NMR and heat-capacity results for Li_1-xZn_x(V_1-yTi_y)₂O₄ with and . For all doping levels the susceptibility curves can be fitted with a Curie-Weiss law. The paramagnetic Curie-Weiss temperatures remain negative with an average value close to that of the pure compound  K. Spin-glass anomalies are observed in the susceptibility, heat-capacity and NMR measurements for both type of dopants. From the temperature dependence of the spin-lattice relaxation rate we found critical-dynamic behavior in the Zn doped compounds at the freezing temperatures. For the Ti-doped samples two successive freezing transitions into disordered low-temperature states can be detected. The temperature dependence of the heat capacity for Zn-doped compounds does not resemble that of canonical spin glasses and only a small fraction of the total vanadium entropy is frozen at the spin-glass transitions. For pure LiV₂O₄ the spin-glass transition is completely suppressed. The temperature dependence of the heat capacity for LiV₂O₄ can be described using a nuclear Schottky contribution and the non-Fermi liquid model, appropriate for a system close to a spin-glass quantum critical point. Finally an (x/y,T)-phase diagram for the low-doping regime is presented.