Samarium(III) fluoride (SmF<sub>3</sub>) is a slightly hygroscopic solid fluoride. Conditions/substances to avoid are: open flame, moisture, strong acids.
Samarium(III) fluoride can be obtained by reacting SmCl<sub>3</sub> or Sm<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub> with 40% hydrofluoric acid:
Samarium(III) fluoride can also be produced by hydrothermal reaction of samarium nitrate and sodium fluroborate at 200 ðC.
Samarium(III) fluoride reacts with some reducing agents at high temperatures to obtain samarium(II) fluoride:
At room temperature, samarium(III) fluoride has orthorhombic structure with space group Pnma â ò-YF<sub>3</sub> type with lattice constants a = 666,9 pm, b = 705,9 pm, c = 440,5 pm. Above 495 ðC, it has the rhombohedral LaF<sub>3</sub> structure (space group P3cl) â with lattice constants a = 707, c = 724 pm.