Document Type

Article

Publication Version

Published Version

Publication Date

5-12-2015

Journal or Book Title

Physical Review B

Volume

91

Issue

17

First Page

174104

DOI

10.1103/PhysRevB.91.174104

Abstract

The coexistence pressure of two phases is a well-defined point at fixed temperature. In experiment, however, due to nonhydrostatic stresses and a stress-dependent potential energy barrier, different measurements yield different ranges of pressure with a hysteresis. Accounting for these effects, we propose an inequality for comparison of the theoretical value to a plurality of measured intervals. We revisit decades of pressure experiments on the bcc↔hcp transformations in iron, which are sensitive to nonhydrostatic conditions and sample size. From electronic-structure calculations, we find a bcc↔hcp coexistence pressure of 8.4GPa. We construct the equation of state for competing phases under hydrostatic pressure, compare to experiments and other calculations, and address the observed pressure hysteresis and range of onset pressures of the nucleating phase.

Comments

This article is from Physical Review B 91 (2015): 174104, doi:10.1103/PhysRevB.91.174104. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

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