论文标题
研究散装无限层镍中的氢掺入
Investigation of hydrogen incorporations in bulk infinite-layer nickelates
论文作者
论文摘要
无限层（IL）镍是一类新兴的超导体，其中Ni $^{1+} $ Valence State在正方形的平面Nio $ _2 $配位中只能通过替洛弗斯基特阶段的拓扑减少来达到。但是，这种带有氢化试剂的拓扑软化化学仍处于快速发展的阶段，并且存在许多开放问题，尤其是考虑到氢化的可能性。在这里，我们研究了使用X射线衍射和气体提取技术的LANIO $ _3 $对LANIO $ _3 $ toptactic转换的时间依赖性。虽然粉末的氢含量随时间增加，但中子衍射在LANIO $ _2 $晶格中没有氢的负散射。额外的氢似乎仅限于晶界或二次相沉淀。因此，普通晶体结构，以及可能的物理特性，主要的lanio $ _2 $相位的平均晶体结构并不明显受到拓扑转化产生的氢残基的影响。
Infinite-layer (IL) nickelates are an emerging class of superconductors, where the Ni$^{1+}$ valence state in a square planar NiO$_2$ coordination can only be reached via topotactic reduction of the perovskite phase. However, this topotactic soft chemistry with hydrogenous reagents is still at a stage of rapid development, and there is a number of open issues, especially considering the possibility of hydrogen incorporation. Here we study the time dependence of the topotactic transformation of LaNiO$_3$ to LaNiO$_2$ for powder samples with x-ray diffraction and gas extraction techniques. While the hydrogen content of the powder increases with time, neutron diffraction shows no negative scattering of hydrogen in the LaNiO$_2$ crystal lattice. The extra hydrogen appears to be confined to grain boundaries or secondary-phase precipitates. The average crystal structure, and possibly also the physical properties, of the primary LaNiO$_2$ phase are therefore not noticeably affected by hydrogen residues created by the topotactic transformation.
