Mechanism of the Body-Centered Cubic—Hexagonal Close-Packed Phase Transition in Iron

See allHide authors and affiliations

Science  06 Nov 1987:
Vol. 238, Issue 4828, pp. 780-783
DOI: 10.1126/science.238.4828.780


The transition from body-centered cubic to hexagonal close-packed phase in iron has been studied in a diamond anvil cell with synchrotron radiation. The hexagonal close-packed phase, when it first appears, has a ratio of lattice parameters that is significantly larger than normal. This is attributed to a displacive mechanism that causes a distortion of the hexagonal close-packed structure in a body-centered cubic matrix. The hexagonal close-packed phase adjacent to a boundary with the body-centered cubic phase is stretched in the c direction and compressed in the a direction when it first forms.