Temperature dependence of the stacking-fault Gibbs energy for Al, Cu, and Ni

Xi Zhang, Blazej Grabowski, Fritz Körmann, Andrei V. Ruban, Yilun Gong, Roger C. Reed, Tilmann Hickel, Jörg Neugebauer

Research output: Contribution to journalArticleScientificpeer-review

22 Citations (Scopus)
123 Downloads (Pure)

Abstract

The temperature-dependent intrinsic stacking fault Gibbs energy is computed based on highly converged density-functional-theory (DFT) calculations for the three prototype face-centered cubic metals Al, Cu, and Ni. All relevant temperature-dependent contributions are considered including electronic, vibrational, magnetic, and explicit anharmonic Gibbs energy contributions as well as coupling terms employing state-of-the-art statistical sampling techniques. Particular emphasis is put on a careful comparison of different theoretical concepts to derive the stacking fault energy such as the axial-next-nearest-neighbor-Ising (ANNNI) model or the vacuum-slab approach. Our theoretical results are compared with an extensive set of previous theoretical and experimental data. Large uncertainties in the experimental data highlight the necessity of complementary parameter-free calculations. Specifically, the temperature dependence is experimentally unknown and poorly described by thermodynamic databases. Whereas calphad derived data shows an increase of the stacking fault energy with temperature for two of the systems (Cu and Ni), our results predict a decrease for all studied systems. For Ni, the temperature induced change is in fact so strong that in the temperature interval relevant for super-alloy applications the stacking fault energy falls below one third of the low temperature value. Such large changes clearly call for a revision of the stacking fault energy when modeling or designing alloys based on such elements.

Original languageEnglish
Article number224106
Number of pages24
JournalPhysical Review B
Volume98
Issue number22
DOIs
Publication statusPublished - 2018

Fingerprint Dive into the research topics of 'Temperature dependence of the stacking-fault Gibbs energy for Al, Cu, and Ni'. Together they form a unique fingerprint.

Cite this