|
|||||
|
|
Ground-state properties of LiV2O4 and Li1-xZnx(V1-yTiy)2O4 |
|
| Authors: | M Brando N Büttgen V Fritsch J Hemberger H Kaps H-A Krug von Nidda M Nicklas K Pucher W Trinkl A Loidl EW Scheidt M Klemm S Horn |
| Institution: | Experimentalphysik V, Elektronische Korrelationen und Magnetismus, Institut für Physik, Universit?t Augsburg, 86135 Augsburg, Germany, DE Experimentalphysik III, Institut für Physik, Universit?t Augsburg, 86135 Augsburg, Germany, DE Experimentalphysik II, Institut für Physik, Universit?t Augsburg, 86135 Augsburg, Germany, DE |
| Abstract: | We present susceptibility, microwave resistivity, NMR and heat-capacity results for Li1-xZnx(V1-yTiy)2O4 with 0 ? x ? 0.3 and 0 ? y ? 0.3. 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 Θ≈ - 36 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. Received 16 March 2001 and Received in final form 30 October 2001 |
| Keywords: | 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 |
| 本文献已被 SpringerLink 等数据库收录！ | |