Samarium tetraboride

Samarium tetraboride is a binary inorganic compound of samarium and boron with the formula SmB4. It forms black crystals.

Preparation
Samarium tetraboride can be prepared from directly reacting samarium and boron at 2400 °C:


 * Sm + 4B -> SmB4

Physical properties
Samarium tetraboride forms crystals of the orthorhombic crystal system, space group P4/mbm, cell parameters a = 0.7174 nm, c = 0.40696 nm, Z = 4, and a structure like thorium tetraboride.

The compound is formed by a peritectic reaction at a temperature of 2400 °C.

At temperatures of 25 K and 7 K, magnetic transitions occur in the compound.