FeGe1-xSbx:a series of novel kagome metals with noncollinear antiferromagnetism

TL;DR

This study explores how Sb doping affects the structural, charge, and magnetic properties of FeGe kagome metals, revealing suppressed charge density waves, altered magnetic anisotropy, and widespread noncollinear antiferromagnetic order.

Contribution

It provides new insights into the magnetic and structural evolution of FeGe kagome metals with Sb doping, highlighting noncollinear antiferromagnetism and magnetic transitions.

Findings

Charge density wave is suppressed by ~1.5% Sb doping.

Antiferromagnetic transition temperature shifts to 280K with doping.

Noncollinear antiferromagnetic structures are observed below TN for x>0.1.

Abstract

Kagome metals are important for exploring emergent phenomena due to the interplay between band topology and electron correlation.Motivated by the recent discovery of charge density wave in a kagome lattice antiferromagnetic FeGe,we investigate the impact of Sb doping on the structural,charge and magnetic order of FeGe.The charge density wave is rapidly suppressed by Sb doping(~1.5%) and the antiferromagnetic ordering temperature gradually shifts to 280K for FeGe0.7Sb0.3.For FeGe1-xSbx with x>0.1,crystal structures with slightly distorted Fe kagome lattice are formed.Their magnetic anisotropy has significant change,temperature driven spin-reorientation and field-induced spin-flop transition are identified from magnetization measurement.Interestingly,neutron diffraction reveals noncollinear antiferromagnetic structures widely exist below TN for all sample with x>0.1.This noncollinear magnetic orders could possibly be unconventional and resulted from onsite repulsion and filling condition of kagome flat band,as predicted by a recent theoretical work.