Electronic and magnetic properties of the quasi-skutterudite RT2X8 intermetallic compounds

The series $R{T}_2{X}_8$ (R = La–Nd, Sm, Eu, Yb, Ca and Sr; T = Fe, Co, Ni, Ru, Rh and Ir; X = Al, Ga and In) belong to a class of quasi-skutterudite intermetallic compounds which crystallize in the orthorhombic CaCo₂Al₈-type structure with space group $Pbam$ (No. 55). A new member of the series CePd₂Al₈ crystallizes in a monoclinic structure of its own type with space group C2/m (No. 12). While this family of compounds are still largely unexplored, recent studies have revealed the evolution of interesting electronic and magnetic ground states in certain members of the series. Due to an increasing interest in the study of compounds with cage-like structures owing to their promising properties for thermoelectric applications and the search for heavy fermion superconductivity, it is therefore imperative to put into perspective the observations and important results in previous studies on the $R{T}_2{X}_8$ series. Besides the macroscopic properties such as specific heat, transport properties and magnetization, other important results from techniques such as neutron scattering, X-ray absorption spectroscopy and Mössbauer spectroscopy are also presented for some of the compounds.