Anomalous thermal expansion in $\alpha$-titanium

Abstract

We provide a complete quantitative explanation for the anisotropic thermal expansion of hcp Ti at low temperature. The observed negative thermal expansion along the c-axis is reproduced theoretically by means of a parameter free theory which involves both the electron and phonon contributions to the free energy. The thermal expansion of titanium is calculated and found to be negative along the c-axis for temperatures below $\sim$ 170 K, in good agreement with observations. We have identified a saddle-point Van Hove singularity near the Fermi level as the main reason for the anisotropic thermal expansion in $\alpha -$titanium.

article, 4 pages, 3 figures

References in corpus (1)

• An Empirical Tight-Binding Model for Titanium Phase Transformations

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