An Investigation of the Synthesis of the Layered Perovskite RbCa₂Nb₃O₁₀ Using Time‐Resolved in situ High‐Temperature Powder X‐Ray Diffraction.

Abstract

Niobium Niobium I 5100An Investigation of the Synthesis of the Layered Perovskite RbCa 2 Nb 3 O 10 Using Time-Resolved in situ High-Temperature Powder X-Ray Diffraction. -Time-resolved in situ high-temperature powder XRD reveals that the new molten salt approach, combining a 1:4:3 molar ratio of K 2 CO 3 :CaCO 3 :Nb 2 O 5 with a large excess of RbCl, leads to the rapid formation of the title compound at 800°C. The material crystallizes as soon as the Rb flux melts, and the reaction is complete within a few minutes of reaching 800°C. K 2 CO 3 is a necessary component of the reaction mixture. The solid state reaction of a 1.5:4:3 molar ratio of Rb 2 CO 3 :CaCO 3 :Nb 2 O 5 at 800°C also leads to the formation of the title compound in a relatively short time (80 min). -(GESELBRACHT, M. J.; WALTON, R. I.; COWELL, E. S.; MILLANGE, F.; O'HARE*, D.; Chem.

Molten Salt Synthesis of Ceramic Powders

“…Interesting ion-exchange reaction between the solid oxide and molten chloride is reported in the preparation of RbCa 2 Nb 3 O 10 at 800°C (Geselbracht et al, 2002 …”

Investigation into La(Fe/Mn)O3 Perovskites Formation over Time during Molten Salt Synthesis

“…Previous studies on oxide MSS confirmed that quenching the melt does not change the composition of crystal phases by comparison to in situ diffraction data of the melts. 48,50,56 Thus, samples taken using the "feeding-andsampling" procedure are considered to reliably reflect the phases present in the molten salt during MSS.…”

“…Recently, in situ diffraction measurements were used to identify MSS pathways. [48][49][50]56 These studies show that the intermediates formed during MSS can vary, depending on the melt composition, 49 salt/reagent ratio, 56 synthesis temperature, 48−50 and rate of heating. 50 These studies used the "mixing" procedure, some indicating that the formation of intermediates begins prior to the salt melting, 48 limiting the investigation into MSS kinetics.…”

“…[48][49][50]56 These studies show that the intermediates formed during MSS can vary, depending on the melt composition, 49 salt/reagent ratio, 56 synthesis temperature, 48−50 and rate of heating. 50 These studies used the "mixing" procedure, some indicating that the formation of intermediates begins prior to the salt melting, 48 limiting the investigation into MSS kinetics. In addition, these in situ diffraction studies do not track the product particle shape or size during MSS.…”