Abstract
As the simplest example of geometrical frustration, the two-dimensional triangular lattice antiferromagnet exhibits the mismatch between the lattice geometry and spin-exchange interaction, which has been the subject of intensive studies due to its exotic quantum phenomena. Here, we performed detailed studies of the magnetic structures and spin wave excitations by neutron powder diffraction and inelastic neutron scattering measurements on the triple-perovskite oxides Ba3MNb2O9(M = Co, Ni, and Mn) with triangular-lattice geometry. The interplay between the frustrated interaction and easy-plane/axis anisotropy gives rise to two magnetic phase transition temperatures for Ba3CoNb2O9(Ba3MnNb2O9) and only one for Ba3NiNb2O9. The linear spin-wave theory +1/S calculations indicate that both spatial dimensionality and the spin size have a significant impact on the strength of quantum fluctuations, which lead to their different magnetic ground states and exotic physical properties.
| Original language | English |
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| Pages (from-to) | 6617-6625 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 34 |
| Issue number | 14 |
| DOIs | |
| State | Published - Jul 26 2022 |
Funding
H.Z. and J.M. gratefully acknowledge the helpful discussions of Dr. Martin Mourigal, the Georgia Institute of Technology. J.J., M.Z., M.F.S., G.T.L., and J.M. thank the financial support from the National Science Foundation of China (Nos. U2032213, 11774223, and 12004243), the interdisciplinary program Wuhan National High Magnetic Field Center (Grant No. WHMFC 202122), Huazhong University of Science and Technology, and the National Key Research and Development Program of China (Grant No. 2018YFA0704300). G.T.L. thanks the project funded by China Postdoctoral Science Foundation (Grant No. 2019M661474). J.M. thanks a Shanghai talent program. Q.H. and H.Z. thank the support from NSF-DMR-2003117. The ND experiment was performed at HB-2A of HFIR, and INS experiments were performed at HYSPEC of SNS and DCS of NCNR. A portion of this research used resources at the High Flux Isotope Reactor and the Spallation Neutron Source, DOE Office of Science User Facilities operated by the Oak Ridge National Laboratory.