Non-Fermi-liquid behaviour in the heavy-fermion system

摘要: In heavy-fermion systems with 4f or 5f atoms (such as Ce U) the competition between on-site moment compensation by Kondo effect and long-range RKKY interaction localized magnetic moments leads to possibility of either a non-magnetic magnetically ordered ground state. However, even in case no order exemplified , short-range dynamic intersite correlations are observed. Yet, thermodynamic transport properties this alloy at very low temperatures T resemble those Fermi liquid (FL). Upon alloying Au, incommensurate antiferromagnetism is observed for x > 0.1. For = 0.1 where specific heat C depends on susceptibility T-dependent part electrical resistivity . This marked contrast FL behaviour It suggested that low-energy spin excitations origin these non-Fermi-liquid (NFL) anomalies which occur zero-temperature quantum phase transition. Large fields B restore behaviour. The low-T range extends towards higher increasing B, crossover temperature varying roughly linearly B. Apart from changing Au concentration x, - transition can be tuned applying pressure p antiferromagnetic samples 0.3, NFL critical pressure. 0.2, we likewise observe logarithmic divergence C/T 6.9 kbar recover Finally, report remarkable `universality' system M Pd, Pt: regardless how reached (alloying different elements M, concentration, pressure), versus ln curves practically identical. Possible origins discussed.