k=0 magnetic structure and absence of ferroelectricity in SmFeO3

TL;DR

This study investigates the magnetic structure of SmFeO3 using neutron diffraction and spectroscopy, revealing a collinear antiferromagnetic order and the absence of ferroelectricity despite magneto-elastic coupling.

Contribution

The paper provides detailed magnetic structure determination of SmFeO3 and clarifies its lack of ferroelectricity, challenging previous reports of multiferroic behavior.

Findings

SmFeO3 has a k=0 G-type collinear antiferromagnetic structure.

No evidence of ferroelectricity was observed despite magneto-elastic coupling.

Magneto-elastic coupling occurs at the Néel temperature (~675 K).

Abstract

SmFeO3 has attracted considerable attention very recently due to the reported multiferroic properties above room-temperature. We have performed powder and single crystal neutron diffraction as well as complementary polarization dependent soft X-ray absorption spectroscopy measurements on floating-zone grown SmFeO3 single crystals in order to determine its magnetic structure. We found a k=0 G-type collinear antiferromagnetic structure that is not compatible with inverse Dzyaloshinskii-Moriya interaction driven ferroelectricity. While the structural data reveals a clear sign for magneto-elastic coupling at the N\'eel-temperature of ~675 K, the dielectric measurements remain silent as far as ferroelectricity is concerned.