2015/06/16 by Joseph A. M. Paddison, Paddison, Joseph A. M., Andrew B. Cairns +25
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Multiferroics and related materials #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1506.05045
5 pages, 4 figures
arxiv created 2015/06/16 · openalex publication_date 2015/06/16 · arxiv updated 2015/06/17 · openalex created_date 2022/09/01 · openalex updated_date 2026/07/28
The frustrated pyrochlore antiferromagnet Gd2Ti2O7 has an unusual partially-ordered magnetic structure at the lowest measurable temperatures. This structure is currently believed to involve four magnetic propagation vectors k∈ ⟨ (1)/(2) (1)/(2) (1)/(2) ⟩^* in a cubic 4-k structure, based on analysis of magnetic diffuse-scattering data [J. Phys.: Condens. Matter 16, L321 (2004)]. Here, we present three pieces of evidence against the 4-k structure. First, we report single-crystal neutron-diffraction measurements as a function of applied magnetic field, which are consistent with the selective field-induced population of non-cubic magnetic domains. Second, we present evidence from high-resolution powder neutron-diffraction measurements that rhombohedral strains exist within magnetic domains, which may be generated by magneto-elastic coupling only for the alternative 1-k structure. Finally, we show that the argument previously used to rule out the 1-k structure is flawed, and demonstrate that magnetic diffuse-scattering data can actually be fitted quantitatively by a 1-k structure in which spin fluctuations on ordered and disordered magnetic sites are strongly coupled. Our results provide an experimental foundation on which to base theoretical descriptions of partially-ordered states.