# Magnetic frustration in a metallic fcc lattice

## TL;DR

This study investigates magnetic frustration in a metallic fcc lattice, revealing partial frustration in HoInCu$_4$ and its suppression upon substitution with Cd, leading to a fully ordered magnetic state, supported by neutron scattering and electronic structure analysis.

## Contribution

It provides the first detailed experimental evidence of magnetic frustration in a metallic fcc lattice and shows how chemical substitution tunes this frustration.

## Key findings

- Partial magnetic frustration observed in HoInCu$_4$
- Full magnetic order achieved in HoCdCu$_4$ after substitution
- Electronic density of states influences magnetic interactions

## Abstract

Magnetic frustration in metals is scarce and hard to pinpoint, but exciting due to the possibility of the emergence of fascinating novel phases. The cubic intermetallic compound HoInCu$_4$ with all holmium atoms on an fcc lattice, exhibits partial magnetic frustration, yielding a ground state where half of the Ho moments remain without long-range order, as evidenced by our neutron scattering experiments. The substitution of In with Cd results in HoCdCu$_4$ in a full breakdown of magnetic frustration. Consequently we found a fully ordered magnetic structure in our neutron diffraction experiments. These findings are in agreement with the local energy scales and crystal electric field excitations, which we determined from specific heat and inelastic neutron scattering data. The electronic density of states for the itinerant bands acts as tuning parameter for the ratio between nearest-neighbor and next-nearest-neighbor interactions and thus for magnetic frustration.