Scholarlink

<p>The preparation of Zintl phases with pronounced spin-orbit coupling has received substantial scientific interest because of their distinctive electronic properties. In the context of superconductivity and topological phenomena related to band inversion, intermetallic compounds of bismuth have come into focus recently. While bismuth forms a rich variety of Zintl phases with the heavier alkaline-earth metals, there are significantly fewer magnesium compounds. Here we show that high-temperature high-pressure synthesis opens a convenient route for the preparation of Mg<sub>5</sub>Bi<sub>3</sub>H<sub>x</sub> already at moderate conditions. The compound (space group <i>Pnma, a</i> = 11.5399(3) Å, <i>b</i> = 8.9503(2) Å and <i>c</i> = 7.8770(2) Å) adopts a Ca<sub>5</sub>Sb<sub>3</sub>F crystal structure. The minute amounts of hydrogen could only be detected by thermal decomposition of the compound in combination with mass spectroscopy of the gas phase. Direct space analysis of the chemical bonding allowed for allocating the hydrogen position at a partially occupied interstitial site and reveals strongly polar Mg-Bi and Mg-H bonds in accordance with the Zintl concept. Calculated band structures exhibit substantial electronic reorganization upon hydrogen insertion. The combination of advanced analytical tools in concert with modern quantum chemical techniques provides an efficient approach to allocate trace amounts of interstitial atoms stabilizing intermetallic phases.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Locating hydrogen in the Mg5Bi3Hx Zintl phase

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年4月30日

查看全文
  • Teuta Neziraj,
  • Lev Akselrud,
  • Marcus Schmidt,
  • Ulrich Burkhardt,
  • Yuri Grin,
  • Ulrich Schwarz

摘要

The preparation of Zintl phases with pronounced spin-orbit coupling has received substantial scientific interest because of their distinctive electronic properties. In the context of superconductivity and topological phenomena related to band inversion, intermetallic compounds of bismuth have come into focus recently. While bismuth forms a rich variety of Zintl phases with the heavier alkaline-earth metals, there are significantly fewer magnesium compounds. Here we show that high-temperature high-pressure synthesis opens a convenient route for the preparation of Mg5Bi3Hx already at moderate conditions. The compound (space group Pnma, a = 11.5399(3) Å, b = 8.9503(2) Å and c = 7.8770(2) Å) adopts a Ca5Sb3F crystal structure. The minute amounts of hydrogen could only be detected by thermal decomposition of the compound in combination with mass spectroscopy of the gas phase. Direct space analysis of the chemical bonding allowed for allocating the hydrogen position at a partially occupied interstitial site and reveals strongly polar Mg-Bi and Mg-H bonds in accordance with the Zintl concept. Calculated band structures exhibit substantial electronic reorganization upon hydrogen insertion. The combination of advanced analytical tools in concert with modern quantum chemical techniques provides an efficient approach to allocate trace amounts of interstitial atoms stabilizing intermetallic phases.