Control of the third dimension in copper-based square-lattice antiferromagnets
- Univ. of Warwick, Coventry (United Kingdom)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Oxford, Oxford (United Kingdom)
- Univ. of Oxford, Oxford (United Kingdom); Helios, Farnborough (United Kingdom)
- Univ. of Oxford, Oxford (United Kingdom); ETH Zurich, Zurich (Switzerland)
- Durham Univ., Durham (United Kingdom)
- Univ. of Oxford, Oxford (United Kingdom)
- STFC Rutherford Appleton Lab., Oxfordshire (United Kingdom)
- Paul Scherrer Inst. (PSI), Villigen (Switzerland)
- Univ. of Copenhagen, Copenhagen (Denmark)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- State Univ. of New York, Stony Brook, NY (United States); Argonne National Lab. (ANL), Lemont, IL (United States)
- State Univ. of New York, Stony Brook, NY (United States)
- Univ. of Idaho, Moscow, ID (United States)
- Eastern Washington Univ., Cheney, WA (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States)
Using a mixed-ligand synthetic scheme, we create a family of quasi-two-dimensional antiferromagnets, namely, [Cu(HF2)(pyz)2]ClO4 [pyz = pyrazine], [CuL2(pyz)2](ClO4)2 [L = pyO = pyridine-N-oxide and 4-phpy-O = 4-phenylpyridine-N-oxide. These materials are shown to possess equivalent two-dimensional [Cu(pyz)2]2+ nearly square layers, but exhibit interlayer spacings that vary from 6.5713 to 16.777 Å, as dictated by the axial ligands. We present the structural and magnetic properties of this family as determined via x-ray diffraction, electron-spin resonance, pulsed- and quasistatic-field magnetometry and muon-spin rotation, and compare them to those of the prototypical two-dimensional magnetic polymer Cu(pyz)2(ClO4)2. We find that, within the limits of the experimental error, the two-dimensional, intralayer exchange coupling in our family of materials remains largely unaffected by the axial ligand substitution, while the observed magnetic ordering temperature (1.91 K for the material with the HF2 axial ligand, 1.70 K for the pyO and 1.63 K for the 4-phpy-O) decreases slowly with increasing layer separation. Despite the structural motifs common to this family and Cu(pyz)2(ClO4)2, the latter has significantly stronger two-dimensional exchange interactions and hence a higher ordering temperature. Here, we discuss these results, as well as the mechanisms that might drive the long-range order in these materials, in terms of departures from the ideal S = 1/2 two-dimensional square-lattice Heisenberg antiferromagnet. In particular, we find that both spin-exchange anisotropy in the intralayer interaction and interlayer couplings (exchange, dipolar, or both) are needed to account for the observed ordering temperatures, with the intralayer anisotropy becoming more important as the layers are pulled further apart.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1338801
- Alternate ID(s):
- OSTI ID: 1244137
- Report Number(s):
- LA-UR-16-21872; PRBMDO
- Journal Information:
- Physical Review B, Vol. 93, Issue 9; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Magnetic order and enhanced exchange in the quasi-one-dimensional molecule-based antiferromagnet Cu(NO 3 ) 2 (pyz) 3
|
journal | January 2019 |
Magnetic properties of a quasi-two-dimensional Heisenberg antiferromagnet with distorted square lattice
|
journal | June 2017 |
Interplay of Spin and Spatial Anisotropy in Low-Dimensional Quantum Magnets with Spin 1/2
|
journal | December 2018 |
Similar Records
Antiferromagnetism in a Family of S = 1 Square Lattice Coordination Polymers NiX 2 (pyz) 2 (X = Cl, Br, I, NCS; pyz = Pyrazine)
Magnetic order in the S=1/2 two-dimensional molecular antiferromagnet, copper pyrazine perchlorate Cu(Pz){sub 2}(ClO{sub 4}){sub 2}.