Optical Properties of MFe_4P_12 filled skutterudites

TL;DR

This study investigates the optical properties of MFe_4P_12 filled skutterudites with different filling atoms, revealing a metal-insulator transition and minimal impact on lattice dynamics, relevant for thermoelectric applications.

Contribution

It provides experimental infrared reflectance data on four filled skutterudites and analyzes how different filling atoms affect electronic and lattice properties.

Findings

Metal-insulator transition observed from La to U

Filling atoms have limited effect on lattice dynamics

Implications for thermoelectric material design

Abstract

Infrared reflectance spectroscopy measurements were made on four members of the MFe_4P_12 family of filled skutterudites, with M=La, Th, Ce and U. In progressing from M=La to U the system undergoes a metal-insulator transition. It is shown that, although the filling atom induces such dramatic changes in the transport properties of the system, it has only a small effect on lattice dynamics. We discuss this property of the compounds in the context of their possible thermoelectric applications.