# Striped Magnetic Ground State of the Kagome Lattice in Fe4Si2Sn7O16

## TL;DR

This study uncovers a unique magnetic ground state in Fe4Si2Sn7O16, where two-thirds of the spins form canted antiferromagnetic chains while one-third remains dynamically frustrated, revealing complex partial order in kagome lattices.

## Contribution

It experimentally demonstrates a new partial magnetic order in a kagome lattice, including a frustrated liquid-like state, and relates it to theoretical models of symmetry breaking ground states.

## Key findings

- Two-thirds of spins form canted antiferromagnetic chains
- One-third of spins remain in a liquid-like frustrated state
- No lattice distortion observed despite symmetry-breaking propagation vector

## Abstract

We have experimentally identified a new magnetic ground state for the kagome lattice, in the perfectly hexagonal Fe2+ (3d6, S = 2) compound Fe4Si2Sn7O16. Representational symmetry analysis of neutron diffraction data shows that below T_N = 3.5 K, the spins on 2/3 of the magnetic ions order into canted antiferromagnetic chains, separated by the remaining 1/3 which are geometrically frustrated and show no long-range order down to at least T = 0.1 K. Moessbauer spectroscopy confirms that there is no static order on the latter 1/3 of the magnetic ions - i.e., they are in a liquid-like rather than a frozen state - down to at least 1.65 K. A heavily Mn-doped sample Fe1.45Mn2.55Si2Sn7O16 has the same magnetic structure. Although the propagation vector q = (0, 1/2 , 1/2 ) breaks hexagonal symmetry, we see no evidence for magnetostriction in the form of a lattice distortion within the resolution of our data. We discuss the relationship to partially frustrated magnetic order on the pyrochlore lattice of Gd2Ti2O7, and to theoretical models that predict symmetry breaking ground states for perfect kagome lattices.