发表机构
CEA DAM, DIF; Université Paris-Saclay; CEA; Laboratoire Matière en Conditions Extrêmes; CNRS; ENS Paris-Saclay; Centralesupelec（CEA DAM, DIF; 巴黎萨克雷大学; 法国原子能和替代能源委员会; 极端条件物质实验室; 法国国家科学研究中心; 巴黎萨克雷高等师范学院; 中央理工-电院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用NV中心磁力测量，在高达20 GPa压力下研究β-UH3的居里温度，发现其随压力线性下降，斜率-3.86 K/GPa，预测约44 GPa时铁磁性消失并可能出现量子临界点。
AI 中文摘要
稳定相$\eta$-UH$_3$中铁磁性的起源仍存在争议。由于具有高居里温度和较短的铀-铀原子间距，$\eta$-UH$_3$超出了已知铀化合物的系统性规律。压力为调控磁性直至其抑制提供了有力手段，从而为理解其潜在机制提供了宝贵见解，然而$\eta$-UH$_3$的高压行为在很大程度上仍未被探索。在此，我们结合金刚石对顶砧（DAC）中纯$\eta$-UH$_3$合成的进展与宽场氮-空位（NV）中心磁力测量，测量了$\eta$-UH$_3$在高达约20 GPa压力下居里温度的压力依赖性。我们提出了两种数据分析方法：矢量磁场重建和光探测磁共振（ODMR）响应的统计分析，这些方法使我们能够在等压升温过程中直接成像$\eta$-UH$_3$的磁偶极子。我们观察到居里温度随压力线性下降，斜率为$\ ext{d}T_C/\ ext{d}P=-3.86\,(8)$~K/GPa。预测$\eta$-UH$_3$中的铁磁性在约44 GPa时达到0 K，此时可能出现量子临界点。
英文摘要
The origin of ferromagnetism in the stable $β$-UH$_3$ phase is still debated. With a high Curie temperature and a short uranium-uranium interatomic distance, $β$-UH$_3$ is placed outside the known systematics of uranium compounds. Pressure provides a powerful means of tuning magnetism toward its suppression, thereby offering valuable insights into its underlying mechanisms, yet the high-pressure behavior of $β$-UH$_3$ has remained largely unexplored. Here, we combine in the Diamond Anvil Cell (DAC) the development of pure $β$-UH$_3$ synthesis and widefield nitrogen-vacancy (NV) center magnetometry to measure the pressure dependence of the Curie temperature in $β$-UH$_3$ up to about 20~GPa. We present two data analysis methods, vector magnetic field reconstruction and statistical analysis of the optically detected magnetic resonance (ODMR) response, which enable us to directly image the magnetic dipole of $β$-UH$_3$ during isobaric warming. We observe a linear decrease in the Curie temperature with pressure, yielding a slope of $\text{d}T_C/\text{d}P=-3.86\,(8)$~K/GPa. Ferromagnetism in $β$-UH$_3$ is predicted to reach 0~K at approximately 44~GPa, where a quantum critical point may emerge.
