Quasi-two-dimensional magnetic correlations inNi2P2S6probed byP31NMR
Quasi-two-dimensional magnetic correlations inNi2P2S6probed byP31NMR
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DOI：
10.1103/physrevb.102.064429
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发表时间：
2020-04
影响因子：
3.7
通讯作者：
A. Dioguardi;S. Selter;U. Peeck;S. Aswartham;Mihai I. Sturza;R. Murugesan;M. S. Eldeeb;L. Hozoi;B. Büchner;H. Grafe
中科院分区：
文献类型：
--
作者：
A. Dioguardi;S. Selter;U. Peeck;S. Aswartham;Mihai I. Sturza;R. Murugesan;M. S. Eldeeb;L. Hozoi;B. Büchner;H. Grafe
Detailed $^{31}\mathrm{P}$ nuclear magnetic resonance (NMR) measurements are presented on well-characterized single-crystals of antiferromagnetic van der Waals ${\mathrm{Ni}}_{2}{\mathrm{P}}_{2}{\mathrm{S}}_{6}$. An anomalous breakdown is observed in the proportionality of the NMR shift $K$ with the bulk susceptibility $\ensuremath{\chi}$. This so-called $K$--$\ensuremath{\chi}$ anomaly occurs in close proximity to the broad peak in $\ensuremath{\chi}(T)$, thereby implying a connection to quasi-two-dimensional (2D) magnetic correlations known to be responsible for this maximum. Quantum chemistry calculations show that crystal field energy level depopulation effects cannot be responsible for the $K$--$\ensuremath{\chi}$ anomaly. Appreciable transferred hyperfine coupling is observed, which is consistent with the proposed Ni--S--Ni super- and Ni--S--S--Ni super-super-exchange coupling mechanisms. Magnetization and spin-lattice relaxation rate (${T}_{1}^{\ensuremath{-}1}$) measurements indicate little to no magnetic field dependence of the N\'eel temperature. Finally, ${T}_{1}^{\ensuremath{-}1}(T)$ evidences relaxation driven by three-magnon scattering in the antiferromagnetic state.
Detailed $^{31}\mathrm{P}$ nuclear magnetic resonance (NMR) measurements are presented on well-characterized single-crystals of antiferromagnetic van der Waals ${\mathrm{Ni}}_{2}{\mathrm{P}}_{2}{\mathrm{S}}_{6}$. An anomalous breakdown is observed in the proportionality of the NMR shift $K$ with the bulk susceptibility $\ensuremath{\chi}$. This so-called $K$--$\ensuremath{\chi}$ anomaly occurs in close proximity to the broad peak in $\ensuremath{\chi}(T)$, thereby implying a connection to quasi-two-dimensional (2D) magnetic correlations known to be responsible for this maximum. Quantum chemistry calculations show that crystal field energy level depopulation effects cannot be responsible for the $K$--$\ensuremath{\chi}$ anomaly. Appreciable transferred hyperfine coupling is observed, which is consistent with the proposed Ni--S--Ni super- and Ni--S--S--Ni super-super-exchange coupling mechanisms. Magnetization and spin-lattice relaxation rate (${T}_{1}^{\ensuremath{-}1}$) measurements indicate little to no magnetic field dependence of the N\'eel temperature. Finally, ${T}_{1}^{\ensuremath{-}1}(T)$ evidences relaxation driven by three-magnon scattering in the antiferromagnetic state.