https://doi.org/10.1140/epjb/e20020033
Ground-state properties of LiV2O4 and Li1-xZnx(V1-yTiy)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
We present susceptibility, microwave resistivity, NMR and heat-capacity results for
Li1-xZnx(V1-yTiy)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.
PACS: 75.50.Lk – Spin glasses and other random magnets / 71.27.+a – Strongly correlated electron systems; heavy fermions / 71.10.Hf – Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002