The Structure of Solids

· Metals may also show less well packed crystal structures due to Covalent contributions to their inter-atom binding or thermal effects.
· Iron shows this behavior. At Room Temperature, iron is bcc, at 1183 K a phase transition to fcc occurs, and at 1663 K the material reverts to bcc

· For the bcc structure the Coordination Number is 8 and the APF is 0.68.

From: Newey and Weaver, "Materials Principles and Practice," Butterworth (1990)