SPP 1415: Crystalline Non-Equilibrium Phases - Synthesis, Characterisation and In-situ Investigation of the Formation Mechanisms

尽管在过去的几十年中做出了许多努力，但新的特别是亚稳固体的定向合成仍然非常困难。这种合成缺陷的主要原因是缺乏对固体化合物诞生过程中发生的基本结构形成步骤的更深入理解：首先是成核，然后是结晶。理论计算表明，许多新的固体化合物在一定的温度和/或压力范围内应该是稳定的。但是由于在化合物形成的非常早期阶段缺少对主要步骤的知识，这些理论上预测的固体中的大多数不能制备。因此，这些新化合物可能显示出令人兴奋和意想不到的特性的潜力无法被探索，而对于许多重要技术领域的未来发展，发现具有改进甚至新特性的材料是必不可少的。在本优先方案中，应利用现场分析和先进理论方法的快速进展和认识，以发展固体结构形成的主要步骤的原子图。形成机制的理解是至关重要的制备工作组，以推进合成策略，这给出了控制的结构形成步骤，以引导这些对形成亚稳态结晶固体。此外，优先方案应有助于克服在理解结晶固体形成过程中基本的各个反应步骤方面的明显不足。显然，这样的知识是更直接合成亚稳晶体材料的先决条件。优先计划的重点是以下感兴趣的领域：（1）晶体固体的定向合成;（2）固体的结构-性质关系、多晶型物的相对稳定性等方面的全面表征;（3）系统研究原位条件下的结构形成，包括前体和/或瞬时晶体中间体;（4）结构形成的模拟和建模;（5）能量景观的筛选，包括在可获得的压力-温度范围内的新亚稳晶体材料的结构和性质预测。优先方案的一个核心问题是将固体合成、理论计算和模拟以及现场表征技术领域的不同工作组的能力集中起来。综合之间的反馈？理论？原位研究应允许在原子水平上获得对固体形成机制的充分理解。

Despite many efforts made in the past decades, the directed synthesis of new and especially metastable solids remains extremely difficult. The main reason for this synthetic drawback is the lack of a deeper understanding of the fundamental structure forming steps occurring during the birth of a solid compound: first the nucleation followed by crystallisation. Theoretical calculations have shown that many new solid compounds should be stable within a certain temperature and/or pressure regime. But due to the missing knowledge of the primary steps at the very early stages of compound formation, most of these theoretically predicted solids cannot be prepared. As a consequence, the potential of such new compounds possibly displaying exciting and unexpected properties cannot be explored, while for future developments in many important technological fields the discovery of materials with improved or even new properties is indispensable. In the present Priority Programme the rapid progress and perceptions in both the in-situ analytics and advanced theoretical approaches should be exploited with the aim to develop an atomistic picture of the primary steps of structure formation of solids. The understanding of the formation mechanisms is of fundamental importance for preparative working groups in order to advance synthetic strategies, which give control of structure forming steps in order to direct these towards the formation of metastable crystalline solids. Furthermore, the Priority Programme should help to overcome the apparent deficit understanding the fundamental individual reaction steps during the formation of crystalline solids. Obviously, such knowledge is a prerequisite for the more directed synthesis of metastable crystalline materials. The following areas of interest are in the focus of the Priority Programme: (1) directed synthesis of crystalline solids; (2) full characterisation of the solids with respect to structure-property relationships, relative stability of polymorphs and so on; (3) systematic study of structure formation under in-situ conditions including precursors and/or transient crystalline intermediates; (4) simulation and modelling of structure formation; (5) screening of the energy landscape including structure and property prediction of new metastable crystalline materials in the accessible pressure-temperature regime. A central concern of the Priority Programme is to bring together the competences of different working groups in the areas of syntheses of solids, theoretical calculations and simulation and in-situ characterisation techniques. The feedback between synthesis ? theory ? in-situ investigations should allow acquiring a copious understanding of the formation mechanisms of solids on an atomistic level.