论文标题
水晶场状态和候选量子量子冰冰CE $ _ {2} $ hf $ _ {2} $ o $ $ _ {7} $
Crystal-field states and defect levels in candidate quantum spin ice Ce$_{2}$Hf$_{2}$O$_{7}$
论文作者
论文摘要
我们通过中子衍射，热重测定和X射线吸收光谱法报告了pyrohafnate的粉末和单晶样品的合成及其表征。我们评估了非磁性CE $^{4+} $缺陷的量，并使用此结果来解释使用无弹性中子散射观察到的晶体电场横向的光谱。对这些单离子过渡的分析表明，基态双极的偶极 - 八八度和相当程度的自旋晶格耦合。从光谱上获得的晶体电场参数计算出的单离子特性与大量的磁化率数据符合约1K的良好一致。低于该温度，磁化易感性的行为是相关的状态，表示相关的状态，而没有显示磁性长期订单或冻结0.08 K的任何迹象。调查量子问题的异国情调相关状态，例如最近认为存在于Isostresuntural Compounds CE $ _2 $ _2 $ _2 $ _2 $ o $ _7 $和CE $ _2 $ _2 $ zr $ _2 $ o $ o $ _7 $中的八度量子旋转冰。
We report the synthesis of powder and single-crystal samples of the cerium pyrohafnate and their characterization using neutron diffraction, thermogravimetry and X-ray absorption spectroscopy. We evaluate the amount of non-magnetic Ce$^{4+}$ defects and use this result to interpret the spectrum of crystal-electric field transitions observed using inelastic neutron scattering. The analysis of these single-ion transitions indicates the dipole-octupole nature of the ground state doublet and a significant degree of spin-lattice coupling. The single-ion properties calculated from the crystal-electric field parameters obtained spectroscopically are in good agreement with bulk magnetic susceptibility data down to about 1 K. Below this temperature, the behavior of the magnetic susceptibility indicates a correlated regime without showing any sign of magnetic long-range order or freezing down to 0.08 K. We conclude that Ce$_2$Hf$_2$O$_{7}$ is another candidate to investigate exotic correlated states of quantum matter such as the octupolar quantum spin ice recently argued to exist in the isostructural compounds Ce$_2$Sn$_2$O$_7$ and Ce$_2$Zr$_2$O$_7$.
