Abstract
[Ni(HF2)(3-Clpyridine)4]BF4 (NBCT) is a one-dimensional, S=1 spin chain material that shows no magnetic neutron Bragg peaks down to temperatures of 0.1 K. Previous work identified NBCT as being in the Haldane phase and near a quantum phase transition as a function of D/J to the large-D quantum paramagnet phase (QPM), where D is the axial single-ion anisotropy and J is the intrachain superexchange. Herein, inelastic neutron scattering results are presented on partially deuterated, B11-enriched NBCT polycrystalline samples in zero magnetic field and down to temperatures of 0.3 K. Comparison to density matrix renormalization group calculations yields D/J=1.51 and a significant rhombic single-ion anisotropy E (E/D≈0.03, E/J≈0.05). These D, J, and E values place NBCT in the large-D QPM phase but precipitously near a quantum phase transition to a long-range ordered phase.
| Original language | English |
|---|---|
| Article number | 094431 |
| Journal | Physical Review B |
| Volume | 101 |
| Issue number | 9 |
| DOIs | |
| State | Published - Mar 1 2020 |
Funding
D.M.P. and A.A.P. are supported through the Scientific User Facilities Division of the Department of Energy (DOE) Office of Science, sponsored by the Basic Energy Science (BES) Program, DOE Office of Science. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL). J.H. was supported by the U.S. DOE Office of Science, sponsored by the BES Program in Materials Sciences and Engineering Division of ORNL and by the Polish National Agency of Academic Exchange (NAWA) under Contract No. PPN/PPO/2018/1/00035. Aspects of this work were partially supported by funding provided by the National Science Foundation via Grants No. DMR-1703003 (J.L.M.) and No. DMR-1708410 (M.W.M.). A portion of this work was performed at the National High Magnetic Field Laboratory, which is supported by National Science Foundation Cooperative Agreement No. DMR-1644779 and the state of Florida. We acknowledge C. Batista, A. Tsvelik, and G. E. Granroth for conversations about analyzing the data. We acknowledge M. Whangbo for a calculation of the single-ion anisotropy and G. Alvarez for developing the dmrg++ code . This work has been partially supported by U.S. DOE Grant No. DE-FG02-13ER41967. ORNL is managed by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy. The U.S. Government retains, and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so for U.S. Government purposes.