New layered quaternary BaCu6Sn2As4−x and BaCu6Sn2P4−x phases: Crystal growth and physical properties
New layered quaternary BaCu6Sn2As4−x and BaCu6Sn2P4−x phases: Crystal growth and physical properties
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DOI：
10.1016/j.jallcom.2021.162111
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发表时间：
2022
影响因子：
6.2
通讯作者：
Hanlin Wu;Sheng Li;Xiqu Wang;Sunah Kwon;Wenhao Liu;Gareth A. Ofenstein;Moon J. Kim;B. Lv
中科院分区：
文献类型：
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作者：
Hanlin Wu;Sheng Li;Xiqu Wang;Sunah Kwon;Wenhao Liu;Gareth A. Ofenstein;Moon J. Kim;B. Lv
我们报道了两种具有新结构类型的新四元 BaCu6Sn2As4−x 和 BaCu6Sn2P4−x 相，并通过单晶 X 射线衍射、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和扫描透射电子显微镜 (STEM) 对其进行了充分表征。这两相结晶为四方晶胞，空间群为 I4/mmm(#139)，皮尔逊符号为 tI26。 BaCu6Sn2As4−x 的精化晶格参数面积= 4.164(1) Å,c= 24.088(3) Å，BaCu6Sn2P4−x 的精化晶格参数面积= 4.053(2) Å,c= 24.08(1) Å。它们具有明显的层状特征，由 Ba 原子夹在中间的 Cu6Sn2Pnx(Pn = P, As) 层组成。 Cu6Sn2Pnx层的Cu-Sn骨架与众所周知的Cu2Sb型结构密切相关，并且发现Pn原子占据由Cu和Sn原子紧密堆积引起的两个间隙位置或覆盖在Cu原子形成的方网的顶部。这些化合物还具有低至 2 K 的电传输测量特征。
We report two new quaternary BaCu6Sn2As4−xand BaCu6Sn2P4−xphases with a new structure type, which are fully characterized by single crystal X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These two phases crystallize in tetragonal cell with space groupI4/mmm(#139) and Pearson symbol tI26. The refined lattice parameters area= 4.164(1) Å,c= 24.088(3) Å for BaCu6Sn2As4−x, anda= 4.053(2) Å,c= 24.08(1) Å for BaCu6Sn2P4−x, respectively. They possess a distinct layered feature composed of Cu6Sn2Pnx(Pn = P, As) layers sandwiched by the Ba atoms. The Cu-Sn framework of the Cu6Sn2Pnxlayer is closely related to the well-known Cu2Sb-type structure, and Pn atoms are found occupying two interstitial sites caused by close packing of Cu and Sn atoms or capped on the top of square nets formed by Cu atoms. The compounds are also characterized by electrical transport measurements down to 2 K.