CaCuSi4O10 powder was studied by differential scanning calorimetry and thermogravimetry methods in the range from room temperature to 1450∘C at heating and cooling rates of 20∘C/min. The process of decomposition of cuprorivaite, the composition and transformations of its decomposition products during successive heat treatments were also studied by powder X-ray diffraction and polarization optical microscopy techniques. It was found that CaCuSi4O10 starts to decompose by incongruent melting at a temperature of about 1020∘C, with the minimum of the endothermic DSC peak associated with this process being at 1064.4∘C. CaCuSi4O10 decomposes irreversibly and subsequent cyclic annealings up to a temperature of 1450∘C at heating and cooling rates of 20∘C/min do not cause its re-synthesis. CaCuSi4O10 transforms into a two-phase system consisting of acicular crystals of monoclinic tridymite fused with green glass with the composition CuO−Cu2O−CaO−SiO2, with the weight ratio of tridymite to glass being about 12:13, as a result of two successive annealings up to the temperature of 1450∘C.
@article{arxiv.2605.27455,
title = {High-temperature instability of artificial cuprorivaite: a study using thermal analysis, X-ray powder diffractometry and polarized light microscopy},
author = {Vladimir A. Yuryev and Sergey V. Kuznetsov and Alexander A. Alexandrov and Tatyana V. Yuryeva},
journal= {arXiv preprint arXiv:2605.27455},
year = {2026}
}