Extended Data Fig. 9: Solidification of AgCl-KCl eutectic in a monolayer silica colloidal crystal.

a, An oblique-view SEM image of the monolayer silica colloidal crystal used as a template. b, Plan-view SEM image of a disordered structure observed in AgCl-KCl eutectic solidified (with λ = 1.7 μm) within a monolayer silica colloidal crystal of diameter 560 nm. The solidification direction in b is into the image (z axis), as indicated by the black crossed circle. c, Calculated thermal profile in the bulk of the template during directional solidification of the eutectic-infilled silica colloidal crystal template at a set cooling rate of 10 °C min⁻¹. The isothermal solidification front at the eutectic temperature (591.73 K) is denoted by a thick black line; the eutectic temperature is also indicated by a black line in the key. The black arrow denotes the direction of solidification. d, Cross-sectional-view SEM image, with false colouring denoting AgCl as yellow, and KCl as blue. All scale bars, 1 μm.