Figure 7: Annealing conditions for two double-layer FeSe/SrTiO 3 films.
(a) The sample #1 was annealed at a relatively low but constant temperature of 350 °C for different times. (b) The sample #2 was annealed at gradually increasing temperatures. The colour bar represents the annealing temperature while the bar height represents the annealing time. The annealing is an accumulative process, such as, for a given sample, the annealing is on top of the previous sequence. For example, for the annealing sequence 1 of sample #1, it means the sample #1 has been annealed first at 190 °C for nearly 1 h, then at 350 °C for nearly 15 h.
