Fig. 2
From: Total morphosynthesis of biomimetic prismatic-type CaCO3 thin films
Characterization of the prismatic-type CaCO3 thin films. a, b, Cross-section SEM images showing the three-layered architecture of the thin film, composed of the PVA layer, the granular CaCO3-PAsp transition layer, and the prismatic CaCO3 overlayer in a bottom-to-top view. Three magnified cross-section SEM images of image a showing the gradual structural change in the overlayer in a top-to-bottom view. The white and yellow arrows in images a, b indicate the transition layer-overlayer junction and the transition layer-polymeric substrate interface, respectively. c High-resolution TEM image of a typical prism in the overlayer, which is assigned to vateritic CaCO3. d XRD patterns of prismatic CaCO3 (middle) & CaCO3-SF (upper) thin films and the vaterite standard (lower). Numerous aragonite/calcite peaks in the middle pattern were highlighted with asterisk marks. Indices in the high-resolution TEM c and the XRD pattern d were based on the P3221 structure28, which led to the best fitting to the SAED pattern among several vaterite structures (Supplementary Fig. 13)
