Eu2+ spin dynamics in the filled skutterudites EuM4Sb12 (M = Fe, Ru, Os)

TL;DR

This study investigates how the rattling motion of guest atoms in filled skutterudites influences Eu2+ spin dynamics, revealing a correlation that enhances understanding of cage system behaviors.

Contribution

It provides direct ESR evidence linking rattling motion to inhomogeneous spin dynamics in Eu-filled skutterudites, a novel insight into cage system physics.

Findings

Rattling motion correlates with Eu2+ spin inhomogeneity.

ESR measurements reveal temperature-dependent spin dynamics.

Comparison with clathrate shows similar rattling-spin interaction patterns.

Abstract

We report evidence for a close relation between the thermal activation of the rattling motion of the filler guest atoms, and inhomogeneous spin dynamics of the Eu2+ spins. The spin dynamics is probed directly by means of Eu2+ electron spin resonance (ESR), performed in both X-band (9.4 GHz) and Q-band (34 GHz) frequencies in the temperature interval 4.2 < T < 300 K. A comparative study with ESR measurements on the Beta-Eu8Ga16Ge30 clathrate compound is presented. Our results point to a correlation between the rattling motion and the spin dynamics which may be relevant for the general understanding of the dynamics of cage systems.