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Title: Determining single-ion and spatial exchange anisotropies by pulsed-field magnetometry

Abstract

The magnetic ground-state of the Q1D S = 1 antiferromagnetic (AFM) chain is sensitive to the single-ion anisotropy (D) and the relative strength of intra- (J) and interchain (J’) exchange interactions. The ratios D/J and J’/J dictate the material’s placement on the phase diagram for which three competing phases are known to theoretically exist: Haldane, XY and quantum paramagnetic. We identified [Ni(HF 2)(pyz) 2]SbF 6 (pyz = pyrazine) as a candidate in which to explore proximity to these phases.

Authors:
 [1];  [1];  [2];  [3];  [3]
  1. Eastern Washington Univ., Cheney, WA (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Univ. of Warwick, Coventry (United Kingdom)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1343726
Report Number(s):
LA-UR-17-21122
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; High Magnetic Field Science

Citation Formats

Manson, J. L., Villa, J. A., Singleton, John, Brambleby, J., and Goddard, P. A.. Determining single-ion and spatial exchange anisotropies by pulsed-field magnetometry. United States: N. p., 2017. Web. doi:10.2172/1343726.
Manson, J. L., Villa, J. A., Singleton, John, Brambleby, J., & Goddard, P. A.. Determining single-ion and spatial exchange anisotropies by pulsed-field magnetometry. United States. doi:10.2172/1343726.
Manson, J. L., Villa, J. A., Singleton, John, Brambleby, J., and Goddard, P. A.. Mon . "Determining single-ion and spatial exchange anisotropies by pulsed-field magnetometry". United States. doi:10.2172/1343726. https://www.osti.gov/servlets/purl/1343726.
@article{osti_1343726,
title = {Determining single-ion and spatial exchange anisotropies by pulsed-field magnetometry},
author = {Manson, J. L. and Villa, J. A. and Singleton, John and Brambleby, J. and Goddard, P. A.},
abstractNote = {The magnetic ground-state of the Q1D S = 1 antiferromagnetic (AFM) chain is sensitive to the single-ion anisotropy (D) and the relative strength of intra- (J) and interchain (J’) exchange interactions. The ratios D/J and J’/J dictate the material’s placement on the phase diagram for which three competing phases are known to theoretically exist: Haldane, XY and quantum paramagnetic. We identified [Ni(HF2)(pyz)2]SbF6 (pyz = pyrazine) as a candidate in which to explore proximity to these phases.},
doi = {10.2172/1343726},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Feb 13 00:00:00 EST 2017},
month = {Mon Feb 13 00:00:00 EST 2017}
}

Technical Report:

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  • The magnetic ground state of the quasi-one-dimensional spin-1 antiferromagnetic chain is sensitive to the relative sizes of the single-ion anisotropy (D) and the intrachain (J) and interchain (J') exchange interactions. The ratios D/J and J' /J dictate the material's placement in one of three competing phases: a Haldane gapped phase, a quantum paramagnet, and an XY-ordered state, with a quantum critical point at their junction. We have identified [Ni(HF 2)(pyz) 2] SbF 6, where pyz = pyrazine, as a rare candidate in which this behavior can be explored in detail. Combining neutron scattering (elastic and inelastic) in applied magnetic fieldsmore » of up to 10 tesla and magnetization measurements in fields of up to 60 tesla with numerical modeling of experimental observables, we are able to obtain accurate values of all of the parameters of the Hamiltonian [D = 13.3(1) K, J = 10.4(3) K, and J' = 1.4(2) K], despite the polycrystalline nature of the sample. Density-functional theory calculations result in similar couplings (J = 9.2 K, J' = 1.8 K) and predict that the majority of the total spin population resides on the Ni(II) ion, while the remaining spin density is delocalized over both ligand types. Finally, the general procedures outlined in this paper permit phase boundaries and quantum-critical points to be explored in anisotropic systems for which single crystals are as yet unavailable.« less
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