Helical scattering signatures of strain and electronic textures in YbFe2O4 from three-dimensional reciprocal space imaging

TL;DR

This study uses high-resolution synchrotron data to reveal that YbFe2O4 exhibits an incommensurate charge-density wave with complex scattering signatures, challenging previous assumptions about its ferroelectricity.

Contribution

It provides a detailed structural model showing the incommensurate nature of charge ordering and its impact on scattering signatures in YbFe2O4.

Findings

Charge-density wave is incommensurate and not ferroelectric.

Scattering signatures change from continuous to spotty at the transition.

Three-dimensional fluctuations influence the scattering behavior.

Abstract

The insulating ternary oxide YbFe$_2$O$_4$ displays an unusual frustration-driven incommensurate charge-ordering (CO) transition, linked to possible ferroelectricity. Based on high-resolution synchrotron data, we report a detailed structural model showing that the CO phase is an incommensurate charge-density wave and cannot be ferroelectric, since the electrical dipole moments are also incommensurately modulated. The change between continuous and "spotty" helices of scattering at the CO transition is attributed to three-dimensional fluctuations of the direction of the ordering wavevector.