Samarium (III) fluoride

Crystal structure
__ Sm 3+      __ F -
Crystal system	orthorhombic
Space group	Pnma (No. 62)
Lattice parameters	a = 666.9 pm b = 705.9 pm c = 440.5 pm
Coordination numbers	Sm [9], F [3]
General
Surname	Samarium (III) fluoride
other names	Samarium fluoride Samarium trifluoride
Ratio formula	SmF 3
Brief description	yellowish-white
External identifiers / databases
CAS number 13765-24-7 EC number 237-367-3 ECHA InfoCard 100,033,956 PubChem 83714 Wikidata Q414389
properties
Molar mass	207.36 g mol −1
Physical state	firmly
Melting point	1306 ° C
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-311-331 P: 261-280-301 + 310-311
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Samarium (III) fluoride (SmF ₃ ) is a salt of the rare earth metal samarium .

Extraction and presentation

Samarium (III) fluoride can be obtained by reacting samarium (III) oxide with hydrogen fluoride .

${\displaystyle \mathrm {Sm_{2}O_{3}+6\ HF\longrightarrow 2\ SmF_{3}+3\ H_{2}O} }$

properties

At room temperature , samarium (III) fluoride assumes the orthorhombic β-YF ₃ structure with the space group Pnma (space group no. 62) . The lattice constants are a  = 666.9  pm , b  = 705.9 pm and c  = 440.5 pm. Above 495 ° C it takes on the trigonal LaF ₃ structure with the space group P 3 c 1 (space group no. 165) . Here the lattice constants are a  = 707 pm and c  = 724 pm.

Individual evidence

1. ↑ ^{a b} American Elements: Samarium Fluoride , accessed August 1, 2015.
2. ↑ ^{a b} Datasheet Samarium (III) fluoride, anhydrous, powder, 99.99% from Sigma-Aldrich , accessed on September 29, 2013 ( PDF ).
3. ↑ Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 254.
4. ↑ K. Rotereau, Ph. Daniel, A. Desert, JY Gesland: The high-temperature phase transition in samarium fluoride, SmF ₃ : structural and vibrational investigation. In: Journal of Physics: Condensed Matter , 1998 , 10 , pp. 1431-1446, doi : 10.1088 / 0953-8984 / 10/6/026 .