Fig. 2: HRTEM characterizations along the thickness direction.
From: Challenging the ideal strength limit in single-crystalline gold nanoflakes through phase engineering
a HRTEM image of a random area in an 11.7 nm-thick gold nanoflake showing hexagonal lattice structures (highlighted by a blue frame). b HRTEM image of a zoom-in region in a, where the distance between the nearest edge-on atomic planes is ≈0.25 nm (highlighted by a blue frame). c SAED pattern corresponding to a, matching HCP structure viewing along the <0001> beam direction. d HRTEM image of a random area in a 13.7 nm-thick gold nanoflake displaying hexagonal lattice structures (highlighted by a red frame). e HRTEM image of a zoom-in region in d, revealing a distance of ≈0.15 nm between the nearest edge-on atomic planes (highlighted by a red frame), corresponding to FCC structure viewing along the <111> beam direction. f Statistical analysis of the interplanar spacing in gold nanoflakes with different thicknesses. Error bars represent standard deviations for at least 6 independent measurements for each sample. Blue dotted line, the theoretical value (0.249 nm) of the interplanar spacing of HCP lattice structure viewing along the <0001> beam direction. Red dotted line, the theoretical value (0.144 nm) of the interplanar spacing of FCC lattice structure viewing along the <111> beam direction. The gradient color bar (from blue to red) indicates the phase transformation range, source data are provided as a Source Data file.
