Molecular magnetism and crystal field effects in the Kondo system Ce$_3$Pd$_{20}$(Si,Ge)$_6$ with two Ce sublattices

TL;DR

This paper investigates the complex magnetic and electronic behaviors of Ce3Pd20(T,Si)6, highlighting the Kondo effect, crystal field splitting, and frustration effects, and introduces a molecular magnetism model involving Ce2 cubes.

Contribution

It presents a detailed analysis of the Kondo effect and crystal field splitting in Ce3Pd20(T,Si)6, and develops a novel molecular magnetism model with Ce2 cubes to explain observed phenomena.

Findings

Logarithmic resistance growth confirms Kondo effect

Two-scale behavior explained by crystal field splitting

Frustration effects enhance specific heat

Abstract

The unusual electronic and magnetic properties of the systems Ce$_3$Pd$_{20}$T$_6$ (T = Ge, Si) with two non-equivalent Ce positions are discussed. The logarithmic growth of resistance for both the systems confirms the presence of the Kondo effect in the two respective temperature ranges. The two-scale behavior is explained by consecutive splitting of Ce ion levels in the crystal field. The effects of the frustration caused by the coexistence of the different positions of cerium are treated, which may also significantly enhance the observed values of specific heat. A model of "molecular magnetism" with Ce2 cubes is developed.