Short-range magnetic correlations in quasicrystalline i-Tb-Cd

TL;DR

This study uses neutron scattering to investigate local magnetic correlations in quasicrystalline i-Tb-Cd, revealing Ising-like Tb$^{3+}$ moments aligned along local axes and modeling their configurations to match experimental diffuse scattering data.

Contribution

It introduces a simple Ising-type model for Tb$^{3+}$ moments in quasicrystals and compares simulated scattering with experimental data to identify likely magnetic configurations.

Findings

Tb$^{3+}$ moments align along local five-fold axes

Diffuse scattering matches model predictions for certain configurations

Higher-order intercluster correlations influence magnetic scattering

Abstract

We report on elastic and inelastic neutron scattering from single-grain isotopically-enriched samples to elucidate the local magnetic correlations between Tb$^{3+}$ moments in quasicrystalline i-Tb-Cd. The inelastic neutron scattering measurements of the CEF excitations demonstrated that the Tb$^{3+}$ moments are directed primarily along the local five-fold axes of the Tsai-type cluster as was found for the TbCd6 approximant phase. Based on the inelastic measurements, we consider of a simple Ising-type model for the moment configurations on a single Tb$^{3+}$ icosahedron and enumerate the lowest energy moment configurations. We then calculate the diffuse scattering from these configurations and compare with the experimental magnetic diffuse scattering measurements to identify the most likely single cluster moment configurations and find reasonable agreement between the broad features observed in our scattering simulations. We further consider the role of higher-order (longer range) intercluster correlations for the magnetic scattering.