# Frustrated Magnetism in FeGe3O4 with a Chiral Trillium Network

## TL;DR

FeGe3O4 is a new magnetic material with a unique structure that shows unusual magnetic behavior due to geometric frustration.

## Contribution

FeGe3O4 is a newly identified compound with a chiral trillium network that exhibits frustrated magnetism and no long-range ordering.

## Key findings

- FeGe3O4 crystallizes in the noncentrosymmetric cubic space group P213 with a double-trillium lattice.
- Magnetic interactions in FeGe3O4 show strong frustration with only 34% of expected magnetic entropy recovered at 2.4 K.
- No long-range magnetic ordering is detected down to 0.06 K in FeGe3O4.

## Abstract

The discovery of
new magnetic ground states in geometrically frustrated
lattices remains a central challenge in materials science. Here, we
report the synthesis, structural characterization, and frustrated
magnetic properties of FeGe3O4, a newly identified
compound that crystallizes in the noncentrosymmetric cubic space group P213. In this structure, Fe atoms form an intricate
double-trillium lattice with nearest-neighbor Fe–Fe distances
of ∼4.2 Å, while Ge2+ ions mediate magnetic
interactions through Fe–Ge–Fe pathways. Field-dependent
magnetization at 2 K shows a pronounced nonlinearity, reaching a maximum
moment of 2.55(3) μB/Fe2+ at 70 kOe without
evidence of saturation. Magnetic susceptibility, heat capacity, and
neutron scattering collectively reveal the onset of short-range magnetic
interactions near 5 K, with no long-range ordering detected down to
0.06 K. Specific heat measurements demonstrate strong frustration:
only ∼34% of the expected magnetic entropy is recovered at
2.4 K. Taken together, these results establish FeGe3O4 as a rare example of a geometrically frustrated trillium
lattice magnet, offering a promising platform for exploring exotic
quantum magnetic phenomena.