Fabrication of KSr2Nb5O15 particles with high aspect ratio by two-step molten salt synthesis

•The KSr2Nb5O15 particles with high aspect ratio (>50) were synthesized by MSS.•The product is an ideal template for fabricating fiber with tungsten bronze structure.•KSN crystal growth was controlled by defect reaction mechanism for MSS.

KSr2Nb5O15 (KSN) particles with high aspect ratios (>50) were synthesized by a two-step molten salt synthesis from two kinds of seeds. The effect of KSN seed on the particles size and morphology was investigated, and the crystal growth mechanism was discussed. The results show that only seeds with (0 0 1) surface act as a site for further growth. KSN particles synthesized by the two-step MSS preserved the shape of seed and had a high aspect ratio. When the rod-like seed prepared by a molten salt synthesis was used, the aspect ratio of obtained particles increased to a maximum value (40–60 μm in length and 0.5–1 μm in diameter) at the seed content of 10 wt%, then decreased with the increasing of seed content. The product is an ideal template for fabricating fiber with tungsten bronze structure by a combination of the co-extrusion and template grain growth process.

Graphical abstractKSr2Nb5O15 (KSN) particles were synthesized by a two-step molten salt synthesis from two kinds of seeds, e.g. irregular seeds by the conventional mixed-oxide (CMO) method and rod-like seeds by the molten salt synthesis (MSS) method were obtained. The KSN particles with high aspect ratio (>50) were synthesized by adding 10 wt% KSN rod-like seed, which are ideal templates for fabrication of textured ceramics and fiber.Figure optionsDownload full-size imageDownload as PowerPoint slide