Figure 1 X-ray diffraction patterns for CaCO3 crystals precipitated at 25, 50, 70, and 80 °C.

Figure 2 Bar chart of different polymorphs fractions by mass obtained at the synthesis temperatures (25-80 °C).

Figure 3 SEM images of calcium carbonate crystals precipitated at (a) 25 °C,(b) 30 °C, (c) 40 °C, (d) 50 °C, (e) 60 °C, (f) 70 °C, and (g) 80 °C.

Table 1. Fractions of polymorphs of calcium carbonate formed at each temperature (25-80°C) by mass.

Temperature (°C)

25

30

40

50

60

70

80

Vaterite

0.961

0.925

0.698

0.014

0.424

0.794

0.742

Calcite

0.039

0.075

0.302

0.986

0.576

0.154

0.258

Aragonite

0

0

0

0

0

0.053

0

Table 1:Fractions of various polymorphs of calcium carbonate formed at each temperature (25-80 °C).