Figure 2

Evolution of a Au nanocone apex under an electron beam and an intense electric field, from ordered to disordered to field-evaporated phase. (a) Number of atomic layers removed as a function of time t . (b)–(j) Extracted frames from In Situ TEM Movies 1 and 2 in Supplemental Material [27], corresponding to the points labeled b–j in (a). In the first and crystalline regime [orange, (b)–(d)], no electrical bias was applied and the electron beam was first turned on, then off, and then turned on again (note the truncated x axis); in the second and disordered regime [red, (e)–(g)], the electron beam was on and a bias from 68 to 80 V was applied; in the third regime [blue, (h)–(j)], the electron beam was on and the external bias was increased until field evaporation occurred (102–140 V). The error bars in (a), with an average height of 0.9 atomic layers, represent the uncertainty in measuring the number of atomic layers. V , F , and r denote the applied voltage, the corresponding electric field, and the tip radius, respectively. The red dotted lines in (b)–(j) mark points of reference. The scale bar in (b) also applies to (c)–(j).