Heavy fermion behavior in the quasi-one-dimensional Kondo lattice CeCo2Ga8

Dimensionality plays an essential role in determining the anomalous non-Fermi liquid properties in heavy fermion systems. So far most heavy fermion compounds are quasi-two-dimensional or three-dimensional. Here we report the synthesis and systematic investigations of the single crystals of the quasi-one-dimensional Kondo lattice CeCo 2 Ga 8 . Resistivity measurements at ambient pressure reveal the onset of coherence at T * ≈ 20 K and non-Fermi liquid behavior with linear temperature dependence over a decade in temperature from 2 to 0.1 K. The specific heat increases logarithmically with lowering temperature between 10 and 2 K and reaches 800 mJ/mol K 2 at 1 K, suggesting that CeCo 2 Ga 8 is a heavy fermion compound in the close vicinity of a quantum critical point. Resistivity measurements under pressure further confirm the non-Fermi liquid behavior in a large temperature–pressure range. The magnetic susceptibility is found to follow the typical behavior for a one-dimensional spin chain from 300 K down to T *, and first-principles calculations predict flat Fermi surfaces for the itinerant f -electron bands. These suggest that CeCo 2 Ga 8 is a rare example of the quasi-one-dimensional Kondo lattice, but its non-Fermi liquid behaviors resemble those of the quasi-two-dimensional YbRh 2 Si 2 family. The study of the quasi-one-dimensional CeCo 2 Ga 8 family may therefore help us to understand the role of dimensionality on heavy fermion physics and quantum criticality. Heavy fermion materials: evidence for a quasi-one-dimensional Kondo lattice Evidence is provided for a heavy fermion material that is an unusual example of a quasi-one-dimensional Kondo lattice system. Heavy fermion materials are compounds with localised magnetic moments that interact strongly with the surrounding conduction electrons, causing a rich variety of exotic behaviour to arise. And when these moments form a periodic array, a Kondo lattice can be formed —where scattering off the moments becomes coherent. An international team of researchers led by Yi-feng Yang and Youguo Shi from the Institute of Physics, Chinese Academy of Sciences now present an unusual example of a Kondo lattice system that is quasi-one-dimensional in nature. Using a combination of experiments and first-principles calculations they show that the cerium atoms in single crystals of CeCo 2 Ga 8 form chains, leading to quasi-one-dimensional Kondo lattice behaviour and unusual quantum critical scalings that are not expect