Possible monoclinic distortion of Mo2GaC under high pressure

In this work, we present high-pressure diffraction results of the Mo-based Mn + 1AXn phase, Mo2GaC. A diamond anvil cell was used to compress the material up to 30 GPa, and x-ray diffraction was used to determine the structure and unit cell parameters as a function of pressure. Somewhat surprisingly...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of applied physics 2020-04, Vol.127 (14)
Hauptverfasser: Nikolaevsky, Mark, Friedman, Roee, Dahlqvist, Martin, Hornik, Mishael, Sterer, Eran, Barsoum, Michel W., Rosen, Johanna, Melchior, Aviva, Caspi, El’ad N.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:In this work, we present high-pressure diffraction results of the Mo-based Mn + 1AXn phase, Mo2GaC. A diamond anvil cell was used to compress the material up to 30 GPa, and x-ray diffraction was used to determine the structure and unit cell parameters as a function of pressure. Somewhat surprisingly, we find that, at 295 ± 25 GPa, the bulk modulus of Mo2GaC is the highest reported of all the MAX phases measured to date. The c/a ratio increases with increasing pressure. At above 15 GPa, a splitting in the (1 0 0) reflection occurs. This result, coupled with new density functional theory calculations, suggests that a second order phase transition to possibly a mixture of hexagonal and monoclinic structures may explain this splitting. Such experimentally and theoretically supported phase transitions were not predicted in previously published calculations.
ISSN:0021-8979
1089-7550
1089-7550
DOI:10.1063/1.5140182