# On magnetic structure of CuFe2Ge2: constrains from the 57Fe Mossbauer spectroscopy

## TL;DR

This study uses 57Fe Mossbauer spectroscopy to investigate the magnetic structure of CuFe2Ge2, revealing a complex double-Q spin density wave state that challenges previous neutron scattering and band structure interpretations.

## Contribution

It provides new insights into the magnetic ordering of CuFe2Ge2, suggesting a mixed paramagnetic and magnetically ordered state not fully captured by prior studies.

## Key findings

- Observation of a superposition of paramagnetic and magnetic signals below T_N
- Evidence for a double-Q spin density wave magnetic structure
- Reevaluation of previous neutron scattering data needed

## Abstract

57Fe Mossbauer spectroscopy measurements were performed on a powdered CuFe2Ge2 sample that orders antiferromagnetically at ~ 175 K. Whereas a paramagnetic doublet was observed above the Neel temperature, a superposition of paramagnetic doublet and magnetic sextet (in approximately 0.5 : 0.5 ratio) was observed in the magnetically ordered state, suggesting a magnetic structure similar to a double-Q spin density wave with half of the Fe paramagnetic and another half bearing static moment of ~ 0.5 - 1 mu_B. These results call for a re-evaluation of the recent neutron scattering data and band structure calculations.