Effect of Iron Vacancies on Magnetic Order and Spin Dynamics of the Spin Ladder BaFe2-δS1.5Se1.5

Published

June 13, 2022

Author(s)

Zengjia Liu, Xiao-Sheng Ni, Lisi Li, Hualei Sun, Feixiang Liang, Benjamin Frandsen, Andrew D. Christianson, Clarina dela Cruz, Zhijun Xu, Dao-Xin Yao, Jeffrey Lynn, Robert J. Birgeneau, Kun Cao, Meng Wang

Abstract

Quasi-one-dimensional iron chalcogenides possess various magnetic states depending on the lattice distortion, electronic correlations, and presence of defects. We present neutron diffraction and inelastic neutron scattering experiments on the spin ladder compound BaFe_2-δS_1.5Se_1.5 with ∼6% iron vacancies. The data reveal that long-range magnetic order is absent, while the characteristic magnetic excitations that correspond to both the stripe- and block-type antiferromagnetic correlations are observed. First-principles calculations support the existence of both stripe and block-type antiferromagnetic short-range order in the experimental sample. The disappearance of long-range magnetic order may be due to the competition between these two magnetic orders, which is greatly enhanced for a certain concentration of iron vacancies, which we calculate to be about 6%, consistent with the measured iron vacancy concentration. Our results highlight how iron vacancies in the iron-based spin ladder system strongly influence the magnetic ground state.

Citation

Physical Review B

Volume

105

Issue

21

Pub Type

Journals

Keywords

Iron chalcogenides, one-dimensional magnetism, neutron diffraction, spin ladder, magnetic correlations

Citation

Liu, Z. , Ni, X. , Li, L. , Sun, H. , Liang, F. , Frandsen, B. , Christianson, A. , dela Cruz, C. , Xu, Z. , Yao, D. , Lynn, J. , Birgeneau, R. , Cao, K. and Wang, M. (2022), Effect of Iron Vacancies on Magnetic Order and Spin Dynamics of the Spin Ladder BaFe_2-δS_1.5Se_1.5, Physical Review B (Accessed October 10, 2025)