$\left[\mathrm{Ni}({\mathrm{HF}}_2\right)(3-\text{Clpyridine}){}_4]{\mathrm{BF}}_4$ (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, ${}^{11}\mathrm{B}$-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 $E$ ($E/D\approx 0.03, E/J\approx 0.05$). 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.

中文翻译：

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各向异性S = 1自旋链[Ni（HF2）（3-氯吡啶）4] BF4的非弹性中子散射研究

$[你（{\mathrm{高频}}_2）（3-\text{氯吡啶}）{}_4]{\mathrm{高炉}}_4$ （NBCT）是一维的， $\mathrm{小号}=\mathrm{1个}$ 自旋链材料在低至0.1 K的温度下无磁中子布拉格峰。先前的工作将NBCT确定为处于Haldane相并且接近于量子相变，这是NCF的函数。 $d/Ĵ$ 到大$d$ 量子顺磁相（QPM），其中 $d$ 是轴向单离子各向异性，并且 $Ĵ$是链内超级交换。在此，非弹性中子散射结果在部分氘代中给出，${}^{11}\mathrm{乙}$零磁场且温度低至0.3 K的高浓度NBCT多晶样品。与密度矩阵重整化组计算的比较得出 $d/Ĵ=1.51$ 和明显的菱形单离子各向异性 $Ë$ （$Ë/d\approx 0.03， Ë/Ĵ\approx 0.05$）。这些$d， Ĵ$和 $Ë$ 值将NBCT放在$d$ QPM相却陡峭地接近量子相，过渡到长程有序相。