Dolyniuk Juli-Anna, Mark Justin, Lee Shannon, Tran Nhon, Kovnir Kirill
Department of Chemistry, University of California, Davis, CA 95616, USA.
Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
Materials (Basel). 2019 Jan 13;12(2):251. doi: 10.3390/ma12020251.
The synthesis, structural characterization, and optical properties of the binary Zintl phases of -EuP₃, -EuP₃, EuP₂, and -K₄P₆ are reported in this study. These crystal structures demonstrate the versatility of P fragments with dimensionality varying from 0D (P₆ rings in -K₄P₆) to 1D chains (EuP₂) to 2D layers (both EuP₃). EuP₂ is isostructural to previously reported SrP₂ and BaP₂ compounds. The thermal stabilities of the EuP₂ and both EuP₃ phases were determined using differential scanning calorimetry (DSC), with melting temperatures of 1086 K for the diphosphide and 1143 K for the triphosphides. Diffuse reflectance spectroscopy indicated that EuP₂ is an indirect semiconductor with a direct bandgap of 1.12(5) eV and a smaller indirect one, less than 1 eV. Both EuP₃ compounds had bandgaps smaller than 1 eV.
本研究报道了二元锌特相-EuP₃、-EuP₃、EuP₂和-K₄P₆的合成、结构表征及光学性质。这些晶体结构展示了磷片段的多样性，其维度从0维（-K₄P₆中的P₆环）到1维链（EuP₂）再到2维层（两种EuP₃）。EuP₂与先前报道的SrP₂和BaP₂化合物同构。使用差示扫描量热法（DSC）测定了EuP₂和两种EuP₃相的热稳定性，二磷化物的熔点为1086 K，三磷化物的熔点为1143 K。漫反射光谱表明EuP₂是一种间接半导体，其直接带隙为1.12(5) eV，间接带隙较小，小于1 eV。两种EuP₃化合物的带隙均小于1 eV。
