Toward reducing the formation temperature of diopside via wet-chemical synthesis routes using chloride precursors

TL;DR

This study compares wet-chemical synthesis methods for diopside to lower its formation temperature, finding that coprecipitation with controlled conditions enables low-temperature, nanoparticulate diopside formation with improved control over structure.

Contribution

It demonstrates that specific coprecipitation techniques can effectively reduce diopside formation temperature and control nanoparticle structure, advancing ceramic synthesis methods.

Findings

Sol-gel methods produce multiphase, low-crystallinity structures.

One-step coprecipitation yields nano-diopside at low temperature.

Dropwise coprecipitation achieves direct crystallization with moderate crystallinity.

Abstract

Reducing the formation temperature of single-phase multioxides is one of the classic challenges in ceramic processing, including wet-chemical synthesis routes. Toward pursuing this aim for diopside (MgCaSi2O6), the merit of different sol-gel and coprecipitation processes using the related chloride precursors followed by calcination was compared from the viewpoints of crystallinity and homogeneity. In accordance to the results, the use of the sol-gel techniques, directed with/without an alkaline catalyst, gave rise to the unfavorable creation of multiphase and low-crystallinity structures. Regarding the coprecipitation methods, the one-step addition of a precipitant agent is accompanied by an indirect low-temperature formation of nano-diopside, while a direct crystallization into this phase was explored in the dropwise condition, albeit with a lower crystallinity. Thus, by employing a suitable synthesis processing, it is feasible to take control of a wide range of nanoparticulate diopside-based structures achieved after a low-temperature calcination.