Corrigendum: The RAPTR furnace: a rapid heating and cooling sample furnace for in situ X-ray scattering studies of temperature-induced reactions (Journal of Applied Crystallography (2024) 57 (88-93) DOI: 10.1107/S1600576723011020)

For the article by Hu et al. (2024), errors in the structural models fitted to the diffraction data for an example solid-state reaction are corrected. The corrections are confined to Section 5 of that article, which illustrates an application of the RAPTR furnace. A revised version of this section is provided below, together with the corrected Fig. 6. For the reaction of PbO and WO₃, the WO₃ polymorph present at the reaction temperature was incorrectly modelled as the polymorph rather than -WO₃. In addition, the reaction intermediate was misidentified as Pb₃WO₆ instead of Pb₂WO₅. These errors affected the quantitative phase analysis, reported reaction evolution and mechanistic details. 5. Capturing the fast solid-state reaction of PbO and WO3 The synthesis of the scheelite-type PbWO4 was evaluated as a model stoichiometric solid-state reaction (Formula presented). We note that the initial phase that forms, the Pb2WO5 phase, is richer in the lower valent, more mobile cation than the final product (i.e. Pb). That is, the Pb2WO5 intermediate has a higher Pb2+:W6+ ratio than the PbWO4 product. This may suggest that cations from the more mobile species diffuse or insert into other phases faster than they redistribute. This observation leads to pertinent questions on how the reaction kinetics and stoichiometry of intermediates depend on the relative mobility of ions within the target product. (Figure presented).