Panoramic Synthesis as an Effective Materials Discovery Tool: The System Cs/Sn/P/Se as a Test Case
Panoramic Synthesis as an Effective Materials Discovery Tool: The System Cs/Sn/P/Se as a Test Case
复制标题
DOI：
10.1021/jacs.7b05423
复制
发表时间：
2017-08-09
影响因子：
15
通讯作者：
Kanatzidis, Mercouri G.
中科院分区：
文献类型：
--
作者：
Haynes, Alyssa S.;Stoumpos, Constantinos C.;Kanatzidis, Mercouri G.
合成新材料的常见方法包括在某些条件下保持在高温下的反应，例如在黑暗中在坚固的容器中加热一段时间，直到判断已经结束。随后对容器内容物的分析仅提供最终产品的知识。在反应过程中可能形成的中间体仍然未知。这种对瞬态中间体的缺乏认识意味着失去了发现材料或了解最终产品如何形成的机会。在这里，我们提出了新的结果，使用一个新兴的原位监测方法，显示出很高的潜力，发现新的化合物。在Cs/Sn/P/Se体系中进行了原位同步辐射X射线衍射研究。将Cs2 Se 2、Sn和PSe 2的粉末混合物加热至650 ℃，然后冷却至室温，同时从反应过程的开始到结束获得连续的原位同步加速器衍射图案。将衍射数据转化为存在的相与温度的关系。在实验中观察到七种已知的晶相在升温时形成：Sn、Cs_2Se_3、Cs_4Se_（16）、Cs_2Se_5、Cs_2Sn_2Se_6、Cs_4P_2Se_9和Cs_2P_2Se_8。六个未知的阶段，也检测到使用原位同步辐射数据作为指导，其中三个被隔离和表征非原位。它们是Cs4 Sn（P2 Se 6）（2）、a-Cs2 SnP 2Se 6和Cs-4（Sn 3Se 8）[Sn（P2 Se 6）]（2）。Cs-4（Sn 3Se 8）[Sn（P2 Se 6）]（2）是一种二维化合物，在50 K以下表现为n型掺杂半导体，在较高温度下表现为半金属。因为所有的晶相都在反应过程中显露出来，我们称这种方法为“全景合成”。
The common approach to the synthesis of a new material involves reactions held at high temperatures under certain conditions such as heating in a robust vessel in the dark for a period until it is judged to have concluded. Analysis of the vessel contents afterward provides knowledge of the final products only. Intermediates that may form during the reaction process remain unknown. This lack of awareness of transient intermediates represents lost opportunities for discovering materials or understanding how the final products form. Here we present new results using an emerging in situ monitoring approach that shows high potential in discovering new compounds. In situ synchrotron X-ray diffraction studies were conducted in the Cs/Sn/P/Se system. Powder Mixtures of Cs2Se2, Sn, and PSe2 were heated to 650 degrees C and then cooled to room temperature while acquiring consecutive in situ synchrotron diffraction patterns from the beginning to the end of the reaction process. The diffraction data was translated into the relationship of phases present versus temperature. Seven known crystalline phases Were observed to form on warming in the experiment: Sn, Cs2Se3, Cs4Se16, Cs2Se5, Cs2Sn2Se6, Cs4P2Se9, and Cs2P2Se8. Six unknown phases were also detected using the in situ synchrotron data as a:guide three of them were isolated and characterized ex situ. These are Cs4Sn(P2Se6)(2), alpha-Cs2SnP2Se6, and Cs-4(Sn3Se8)[Sn(P2Se6)](2). Cs-4(Sn3Se8)[Sn(P2Se6)](2) is a two-dimensional compound that behaves as an n-type doped semiconductor below 50 K and acts more like a semimetal at higher temperatures. Because all crystalline phases are revealed during the reaction, we call this approach "panoramic synthesis".