Amano Patino Midori, Zeng Dihao, Blundell Stephen J, McGrady John E, Hayward Michael A
Inorganic Chemistry Laboratory, Department of Chemistry , University of Oxford , South Parks Road , Oxford OX1 3QR , United Kingdom.
Clarendon Laboratory, Department of Physics , University of Oxford , Parks Road , Oxford OX1 3PU , United Kingdom.
Inorg Chem. 2018 Mar 5;57(5):2890-2898. doi: 10.1021/acs.inorgchem.8b00026. Epub 2018 Feb 13.
The anion-ordered oxide-hydride SrVOH is an antiferromagnetic insulator due to strong correlations between vanadium d electrons. In an attempt to hole-dope SrVOH into a metallic state, a strategy of first preparing SrVTi O phases and then converting them to the corresponding SrVTi OH phases via reaction with CaH was followed. This revealed that the solid solution between SrVO and SrTiO is only stable at high temperature. In addition, reactions between SrVTiO and CaH were observed to yield SrVTiOH not SrVTiOH. This dramatic change in reactivity for a very modest change in initial chemical composition is attributed to an electronic destabilization of SrVOH on titanium substitution. Density functional theory calculations indicate that the presence of an anion-ordered, tetragonal SrMOH phase is uniquely associated with a d electron count and that titanium substitution leads to an electronic destabilization of SrVTi OH phases, which, ultimately, drives further reaction of SrVTi OH to SrVTi OH. The observed sensitivity of the reaction products to the chemical composition of initial phases highlights some of the difficulties associated with electronically doping metastable materials prepared by topochemical reactions.
由于钒d电子之间的强相关性，阴离子有序的氧化物氢化物SrVOH是一种反铁磁绝缘体。为了将SrVOH空穴掺杂成金属态，采用了先制备SrVTi O相，然后通过与CaH反应将其转化为相应的SrVTi OH相的策略。这表明SrVO和SrTiO之间的固溶体仅在高温下稳定。此外，观察到SrVTiO与CaH之间的反应生成的是SrVTiOH而非SrVTiOH。对于初始化学成分的非常微小的变化，反应性出现如此巨大的变化，这归因于钛取代时SrVOH的电子失稳。密度泛函理论计算表明，阴离子有序的四方SrMOH相的存在与d电子数唯一相关，并且钛取代导致SrVTi OH相的电子失稳，最终促使SrVTi OH进一步反应生成SrVTi OH。观察到反应产物对初始相化学成分的敏感性，凸显了与通过拓扑化学反应制备的亚稳材料进行电子掺杂相关的一些困难。
