Crystal field levels resistivity effects

The temperature-dependent electrical resistivity of a good-quality CeAs single crystal, measured by Suzuki et al. (1990), is shown in fig. 120. Apart from the sharp peak at Tf = 7.6 K a broad maximum appears around 60 K, with a Kondo-type behaviour in the higher-temperature region. It was concluded that the Kondo effect is due to the excited Tg crystal-field level, which becomes populated thermally. The value of the resistivity at 1.7 K (70pi2cm) reflects the low carrier concentration. 

Rikken proposed that the EMCA effect could also result from the simultaneous application of a magnetic field and a current to a crystal with an enantiomorphous space group, and that it is a universal property. He showed the existence of this effect in the case of chiral single-walled carbon nanotubes.For most of the investigated tubes, a dependence of the resistance is observed that is odd in both the magnetic field and the current. These observations confirm the existence of EMCA not only for a macroscopic chiral conductor but also for a molecular conductor with chirality on the microscopic level. 

---