Real-time in situ monitoring of the topotactic transformation of TlCu5Se3 into metastable o-TlCu4Se3

• Solid-state transformation TlCu5Se3 → o-TlCu4Se3 was observed by in situ real-time XRD.
• Oxidative copper leaching of TlCu5Se3in concentrated ammonia solution.
• The transformation was followed in a real-time mode, leading to a complete transformation of the sample.

The transformation within the solid state of tetragonal TlCu5Se3 into the metastable orthorhombic form of TlCu4Se3 by oxidative copper leaching in concentrated ammonia solution has been studied in situ by conventional X-ray powder diffraction. The ease with which the reaction occurs illustrates a comparatively high diffusion coefficient typical of copper sulphides and selenides. The diffraction patterns of the parent phase as well as the product remain sharp during the process, indicating strong topotaxy in the first-order transformation that is effectuated by the access of oxygen while the accompanying released copper enters the liquid phase. The transformation was followed in a real-time mode, leading to a complete transformation of the amount probed.

The transformation within the solid state of tetragonal TlCu5Se3 into the metastable orthorhombic form of TlCu4Se3 by oxidative copper leaching in concentrated ammonia solution has been studied in situ by conventional X-ray powder diffraction. The transformation was followed in a real-time mode, leading to a complete transformation of the amount probed.Figure optionsDownload as PowerPoint slide