2006/08/01 by L. C. Chapon, P. G. Radaelli, Chapon, L. C. +8
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Crystal Structures and Properties #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/0608031
openalex publication_date 2006/08/01 · arxiv created 2006/08/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The low-temperature magnetic structure of \HG has been studied by high-resolution powder neutron diffraction. Long-range incommensurate magnetic order sets in at TN∼22K with propagation vector k=(0,0,∼0.18). On cooling below TN, the propagation vector increases and saturates at the commensurate value k=(0,0,0.25). The magnetic structure below TN consists of ferromagnetic layers in the ab-plane stacked in a spiral arrangement along the c-axis. Symmetry analysis using corepresentations theory reveals a point group symmetry in the ordered magnetic phase of 422 (D4), which is incompatible with macroscopic ferroelectricity. This finding indicates that the spontaneous electric polarization observed experimentally cannot be coupled to the magnetic order parameter.