Phase formation and evolution was investigated in the CaO–SiO₂ system in the range of 70–80 mol% CaO. The samples were container-less processed in an aerodynamic levitation system and crystallization was followed in situ by synchrotron x-ray diffraction at the beamline P21.1 at the German electron synchrotron (DESY). Modification changes of di- and tricalcium silicate were observed and occurred at lower temperatures than under equilibrium conditions. Despite deep sample undercooling, no metastable phase formation was observed within the measurement timescale of 1s. For the given cooling rates ranging from 300Ks⁻¹ to about 1Ks⁻¹, no decomposition of tricalcium silicate was observed. No differences in phase evolution were observed between reducing and oxidizing conditions imposed by the levitation gas (Ar and Ar + O₂). We demonstrate that this setup has great potential to follow crystallization in refractory oxide liquids in situ. For sub-second primary phase formation faster detection and for polymorph detection adjustments in resolution have to be implemented.

在 CaO-SiO ₂系统中，在 70-80 mol% CaO 范围内研究了相的形成和演化。样品在空气动力学悬浮系统中进行无容器处理，并通过同步加速器 X 射线衍射在德国电子同步加速器 (DESY) 的束线 P21.1 处原位跟踪结晶。观察到硅酸二钙和硅酸三钙的改性变化，并且发生在比平衡条件更低的温度下。尽管样品深度过冷，但在 1 秒的测量时间尺度内未观察到亚稳态形成。对于给定的冷却速率范围从 300Ks ^-1到大约 1Ks ^-1，没有观察到硅酸三钙的分解。在由悬浮气体（Ar 和 Ar + O ₂）施加的还原和氧化条件之间没有观察到相演变的差异。我们证明了这种设置在原位跟踪难熔氧化物液体中的结晶方面具有很大的潜力。对于亚秒级初级相形成，必须实现更快的检测和多晶型检测的分辨率调整。