The Structure of Cementite

[Peyman 16150]

Cementite has an orthorhombic lattice with approximate parameters 0.45165, 0.50837 and 0.67297 nm. There are twelve iron atoms and four carbon atoms per unit cell, corresponding to the formula Fe3C

 

This figure shows the crystal structure of cementite. The purple atoms represent carbon. Each carbon atom is surronded by eight iron atoms. Each iron atom is connected to three carbon atoms. These connections are not obvious from this figure since only the atoms within the unit cell are illustrated

 

 

 

 

This figure shows the coordination polyhedron, in which eight iron atoms surround a carbon atom. The polyhedron consists of a square base and eight triangles

 

 

 

 

The polyhedra are connected at their corners and edges. This image is created using the Crystalmaker library