Samarium(III) fluoride

Preparation

Samarium(III) fluoride can be obtained by reacting SmCl3 or Sm2(CO3)3 with 40% hydrofluoric acid:

:

:

Samarium(III) fluoride can also be produced by hydrothermal reaction of samarium nitrate and sodium fluroborate at 200 °C.

Properties

Chemical

Samarium(III) fluoride reacts with some reducing agents at high temperatures to obtain samarium(II) fluoride:

: \mathsf{ 4 SmF_3 + C \ \xrightarrow{2000^oC}\ 4 SmF_2 + CF_4 } : \mathsf{ 2 SmF_3 + Sm \ \xrightarrow{1800^oC}\ 3 SmF_2 }

Physical

At room temperature, samarium(III) fluoride has orthorhombic structure with space group Pnma – β-YF3 type with lattice constants a = 666,9 pm, b = 705,9 pm, c = 440,5 pm. Above 495 °C, it has the rhombohedral LaF3 structure (space group P3cl) – with lattice constants a = 707, c = 724 pm.

References

References

1. 王亚军, 刘前, 索全伶, 等. 稀土氟化物的沉淀方法及组成研究[J]. 稀土, 2000, 21(1):14-18.
2. 孙元平, 贾佩云, 王芳, 等. 水热条件下稀土氟化物形貌的规律性生长[J]. 中国陶瓷, 2013(6).
3. (1998-02-16). "The high-temperature phase transition in samarium fluoride, : structural and vibrational investigation". Journal of Physics: Condensed Matter.