Comprehensive Study of Electronic Structure of Rare-Earth (R) Filled Skuttterudites, RPt₄Ge₁₂

Materials whose properties are influenced by presence of f-electrons are of current interest. Experiments on rare-earth filled skutterudites demonstrate an intriguing array of thermodynamic, transport and superconducting properties, and bring to fore theoretical challenges posed by f-electron systems. First principle calculations, such as density functional theory (DFT), sparse in the skutterudites, can provide valuable information about electronic structures that can be compared with experiments, and utilized in further theory development. The talk will discuss a comprehensive electronic structure study on a series of rare earth filled skutterudites, RPt₄Ge₁₂ (R= La, Ce, Pr), aimed at shedding light on aspects that may be useful for understanding some of their properties: consequences of progressive increase of f-electrons in the series; role of correlation “U” between the f-electrons and its importance relative to spin-orbit coupling; the nature and variation of 3D Fermi surfaces with the number of f-electrons and “U”. The calculated Fermi surfaces may be relevant to the currently debated issue of multi-band versus single-band superconductivity; the density of states (DOS) and bands can be compared with resonant photoemission spectroscopy and specific heat measurements, and provide estimates of effective masses; the pseudogaps in DOS may be useful for understanding possible thermoelectric applications. These DFT calculations were cross-checked with VASP and Wien2K programs, and done for different exchange functionals; hence may serve as benchmark calculations for these materials.