Evolution of quantum criticality in the system CeNi9Ge4
| Autor: | Michor, H., Adroja, D. T., Hillier, A. D., Koza, M. M., Manalo, S., Gold, C., Peyker, L., Scheidt, E. -W. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | J. Phys.: Conf. Ser. 344, 012001 (2012) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1742-6596/344/1/012001 |
| Popis: | The heavy fermion system CeNi9Ge4 exhibits a paramagnetic ground state with remarkable features such as: a record value of the electronic specific heat coefficient in systems with a paramagnetic ground state, \gamma = C/T \simeq 5.5 J/molK^2 at 80 mK, a temperature-dependent Sommerfeld-Wilson ratio, R=\chi/\gamma, below 1 K and an approximate single ion scaling of the 4f-magnetic specific heat and susceptibility. These features are related to a rather small Kondo energy scale of a few Kelvin in combination with a quasi-quartet crystal field ground state. Tuning the system towards long range magnetic order is accomplished by replacing a few at.% of Ni by Cu or Co. Specific heat, susceptibility and resistivity studies reveal T_N \sim 0.2 K for CeNi8CuGe4 and T_N \sim 1 K for CeNi8CoGe4. To gain insight whether the transition from the paramagnetic NFL state to the magnetically ordered ground state is connected with a heavy fermion quantum critical point we performed specific heat and ac susceptibility studies and utilized the \mu SR technique and quasi-elastic neutron scattering. Comment: 8 pages, 3 figures, will be published in J.Phys.: Conf. Series (Proceedings of the International & Interdisciplinary Workshop on Novel Phenomena in Intergrated Comples Sciences: From Living to Non-living Systems, Japan, held in Kyoto, October 11-14, 2010) |
| Databáze: | arXiv |
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