Dresden 2020 – wissenschaftliches Programm
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TT 19.3: Vortrag
Montag, 16. März 2020, 17:30–17:45, HSZ 103
Signature of isotropic electric dipole dynamics in BaFe2X3 (X = S/Se) — •yuk tai chan1, seulki roh1, soohyeon shin2,3, tuson park2,3, martin dressel1, and ece uykur1 — 11. Physikalisches Institut, Universität Stuttgart, Germany — 2Department of Physics, Sungkyunkwan University, Suwon, Republic of Korea — 3Center for Quantum Materials and Superconductivity (CQMS), Sungkyunkwan University, Suwon, Republic of Korea
BaFe2S3 (BFS) and BaFe2Se3 (BFSe) hold a rare and interesting quasi-1D Fe-ladder structure. Although they are isostructual, magnetic ground states of these are significantly different: BFSe possesses a block-type antiferromagnetic (AFM) order along the leg with TN ∼ 200 K, whereas BFS forms a stripe-type AFM order along the leg with TN ∼ 100 K. The block-type AFM in BFSe has the potential to generate ferroelectric polarization and hence raise hope for a realization of robust multiferroic order. In this study, polarization-dependent dielectric spectroscopy has been performed on single crystals BFS and BFSe. Counterintuitive to the highly anisotropic quasi-1D structure, nearly isotropic relaxor ferroelectric behaviors are observed for both compounds. The range of temperature for the relaxation in BFSe is ∼ 100 K above that in BFS, which follows their AFM order, TN, and therefore suggests a shrouded relationship between the magnetism and electric dipole dynamics.