The low-temperature magnetic properties and magnetic structure of fully dehydrated black dioptase have been studied by single-crystal neutron diffraction and magnetization measurements in magnetic fields up to 30 T. Here, the intrachain and interchain interactions as well as the anisotropy of the exchange coupling have been determined using inelastic neutron-scattering techniques. Zero-field antiferromagnetic order at K can be described by a commensurate propagation vector of with respect to the hexagonal :H unit cell. The Cu magnetic moments are aligned antiferromagnetically along the axis with about tilt and are coupled ferromagnetically between the chains. The high-field magnetization measurements provide strong evidence for the presence of a spin-flop phase above 8 T. We found that in black dioptase is significantly increased, while is much weaker compared to its counterpart, green dioptase . We suggest that black dioptase behaves like a nearly ideal antiferromagnetic Heisenberg spiral chain with enhanced quantum fluctuations and weak spinon confinement .
Podlesnyak, Andrey A., et al. "Magnetic ground state and magnetic excitations in black dioptase <math><mrow><msub><mi>Cu</mi><mn>6</mn></msub><msub><mi>Si</mi><mn>6</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>18</mn></msub></mrow></math>." Physical Review B, vol. 100, no. 18, Nov. 2019. https://doi.org/10.1103/PhysRevB.100.184401
Podlesnyak, Andrey A., Prokhnenko, Oleksandr, Nikitin, Stanislav E., Kolesnikov, Alexander I., Matsuda, Masaaki, Dissanayake, Sachith E., Prisk, T. R., Nojiri, H., Díaz-Ortega, I. F., Kidder, Michelle K., & Anovitz, Lawrence M. (2019). Magnetic ground state and magnetic excitations in black dioptase <math><mrow><msub><mi>Cu</mi><mn>6</mn></msub><msub><mi>Si</mi><mn>6</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>18</mn></msub></mrow></math>. Physical Review B, 100(18). https://doi.org/10.1103/PhysRevB.100.184401
Podlesnyak, Andrey A., Prokhnenko, Oleksandr, Nikitin, Stanislav E., et al., "Magnetic ground state and magnetic excitations in black dioptase <math><mrow><msub><mi>Cu</mi><mn>6</mn></msub><msub><mi>Si</mi><mn>6</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>18</mn></msub></mrow></math>," Physical Review B 100, no. 18 (2019), https://doi.org/10.1103/PhysRevB.100.184401
@article{osti_1607105,
author = {Podlesnyak, Andrey A. and Prokhnenko, Oleksandr and Nikitin, Stanislav E. and Kolesnikov, Alexander I. and Matsuda, Masaaki and Dissanayake, Sachith E. and Prisk, T. R. and Nojiri, H. and Díaz-Ortega, I. F. and Kidder, Michelle K. and others},
title = {Magnetic ground state and magnetic excitations in black dioptase <math><mrow><msub><mi>Cu</mi><mn>6</mn></msub><msub><mi>Si</mi><mn>6</mn></msub><msub><mi mathvariant='normal'>O</mi><mn>18</mn></msub></mrow></math>},
annote = {The low-temperature magnetic properties and magnetic structure of fully dehydrated black dioptase Cu6Si6O18 have been studied by single-crystal neutron diffraction and magnetization measurements in magnetic fields up to 30 T. Here, the intrachain Jc and interchain Jab interactions as well as the anisotropy of the exchange coupling Jc have been determined using inelastic neutron-scattering techniques. Zero-field antiferromagnetic order at TN=6.7 K can be described by a commensurate propagation vector of k=(0,0,3/2) with respect to the hexagonal R3¯:H unit cell. The Cu magnetic moments are aligned antiferromagnetically along the c axis with about 12° tilt and are coupled ferromagnetically between the chains. The high-field magnetization measurements provide strong evidence for the presence of a spin-flop phase above 8 T. We found that Jc in black dioptase is significantly increased, while Jab is much weaker compared to its counterpart, green dioptase Cu6[Si6O18] 6H2O. We suggest that black dioptase behaves like a nearly ideal S=1/2 antiferromagnetic Heisenberg spiral chain with enhanced quantum fluctuations and weak spinon confinement Jab/Jc~0.02.},
doi = {10.1103/PhysRevB.100.184401},
url = {https://www.osti.gov/biblio/1607105},
journal = {Physical Review B},
issn = {ISSN PRBMDO},
number = {18},
volume = {100},
place = {United States},
publisher = {American Physical Society (APS)},
year = {2019},
month = {11}}
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