Correlated electron behavior and low-temperature magnetic anomalies in CeCo2Al8.

We present a study of the structural, magnetic, transport, and thermal properties for the polycrystalline intermetallic compound CeCo2Al8which crystallizes in orthorhombic structure, space groupPbam. X-ray photoelectron spectroscopy confirms that cerium is in the trivalent state in this compound. Low-temperature magnetic correlations with possible short-range antiferromagnetic ordering below ∼ 4 K are observed. Temperature and field dependent electrical resistivity measurements indicate deviation from metallic behavior. The low-temperature specific heat of CeCo2Al8exhibits -log T upturn in the electronic specific heat below ∼10 K, which is a hallmark of Kondo correlations and strongly correlated electron behavior. Considering all these properties, CeCo2Al8behaves as a moderate Kondo lattice system due to moderate coupling between trivalent cerium and cobalt ions.