Berkelium(III) fluoride

Berkelium(III) fluoride is a binary inorganic compound of berkelium and fluorine with the chemical formula.

Synthesis
The compound can be prepared by treating with a gaseous mixture of  and HF at 600 °C.

Physical properties
Berkelium trifluoride forms a yellow-green solid with two structures. At low temperature, it is orthorhombic (yttrium trifluoride structure), with lattice parameters a = 670  pm, b = 709 pm, and c = 441 pm. At high temperature, it is trigonal (lanthanum trifluoride structure), with lattice parameters a = 697 pm and c = 714 pm. The transition temperature of is between 350 and 600 °C.

Chemical properties
Berkelium trifluoride is reduced by lithium to obtain metallic berkelium:


 * BkF3 + 3Li -> Bk + 3LiF