• Janka, Oliver
• Prots, Yurii
• Zaremba, Nazar
• Touzani, Rachid S.
• Engel, Stefan

Abstract

<jats:title>Abstract</jats:title><jats:p>Investigations in the ternary system Eu–Al–Pt led to the discovery of Eu<jats:sub>4</jats:sub>Al<jats:sub>13</jats:sub>Pt<jats:sub>9</jats:sub>, a new representative exhibiting a coloring variant of the Ho<jats:sub>4</jats:sub>Ir<jats:sub>13</jats:sub>Ge<jats:sub>9</jats:sub> type structure. The orthorhombic structure was refined based on single crystal X-ray diffraction data (<jats:italic>Pmmn</jats:italic>, Wyckoff sequence <jats:italic>e</jats:italic><jats:sup>9</jats:sup><jats:italic>b</jats:italic><jats:sup>3</jats:sup><jats:italic>a</jats:italic><jats:sup>5</jats:sup>, <jats:italic>a</jats:italic> = 415.38(1), <jats:italic>b</jats:italic> = 1149.73(2), <jats:italic>c</jats:italic> = 1994.73(5) pm, <jats:italic>wR</jats:italic>2 = 0.0622, 1901 <jats:italic>F</jats:italic><jats:sup>2</jats:sup> values, 88 variables) and full atomic ordering was observed for all atoms. The structure features a complex [Al<jats:sub>13</jats:sub>Pt<jats:sub>9</jats:sub>]<jats:sup><jats:italic>δ</jats:italic>–</jats:sup> network with the Eu atoms occupying hexagonal prismatic cavities. The bonding situation of this new platinide was investigated via quantum-chemical calculations. According to Density Functional Theory (DFT) the title compound has to be described as a polar intermetallic material with a covalently bonded [Al<jats:sub>13</jats:sub>Pt<jats:sub>9</jats:sub>]<jats:sup><jats:italic>δ</jats:italic>–</jats:sup> polyanion showing strong Pt–Al alongside weak Al–Al and Pt–Pt bonding and Eu cations in the cavities.</jats:p>

Topics

• density
• compound
• single crystal X-ray diffraction
• single crystal
• theory
• density functional theory
• intermetallic