Fig. 1.
(Left) Schematics of ESL apparatus combined with real time in situ micro-Raman and X-ray scattering. A reference laser beam (632.8 nm, 1 mW) incidents on a liquid droplet casting a circular shadow on a position-sensitive detector (PSD). (Right) The levitated KDP solution droplet is prepared at an initial concentration of 20 g/100 mL and undergoes supersaturation (A ∼ I) as it evaporates at a rate of 2.92 × 10−4 mm2/s. During the evaporation, the diameter of the droplet shrinks from 2.5 to 1.25 mm. The contactless environment enables unprecedentedly high degree of supersaturation (S ∼ 4.1) where a very rapid crystallization can be observed within 1 s (H ∼ I). (Scale bar: 1 mm.)