Evolution of Quantum Criticality in CeNi_{9-x}Cu_xGe_4
| Autor: | Peyker, L., Gold, C., Scheidt, E. -W., Scherer, W., Donath, J. G., Gegenwart, P., Mayr, F., Eyert, V., Bauer, E., Michor, H. |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | J. Phys.: Condens. Matter 21 (2009) 235604 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0953-8984/21/23/235604 |
| Popis: | Crystal structure, specific heat, thermal expansion, magnetic susceptibility and electrical resistivity studies of the heavy fermion system CeNi_{9-x}Cu_xGe_4 (0 <= x <= 1) reveal a continuous tuning of the ground state by Ni/Cu substitution from an effectively fourfold degenerate non-magnetic Kondo ground state of CeNi_9Ge_4 (with pronounced non-Fermi-liquid features) towards a magnetically ordered, effectively twofold degenerate ground state in CeNi_8CuGe_4 with T_N = 175 +- 5 mK. Quantum critical behavior, C/T ~ \chi ~ -ln(T), is observed for x about 0.4. Hitherto, CeNi_{9-x}Cu_xGe_4 represents the first system where a substitution-driven quantum phase transition is connected not only with changes of the relative strength of Kondo effect and RKKY interaction, but also with a reduction of the effective crystal field ground state degeneracy. Comment: 15 pages, 9 figures |
| Databáze: | arXiv |
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