МЕХАНИЗМЫ ФАЗОВЫХ ПЕРЕХОДОВ В ПОЛИМОРФАХ Al2SiO5

Translated title of the contribution: Mechanisms of phase transitions between Al2SiO5 polymorphs

A. I. Samtsevich, A. R. Oganov

Research output: Contribution to journalArticlepeer-review

Abstract

In nature Al2SiO5 exists as three polymorphs: kyanite, andalusite and sillimanite, often coexisting in the same rock. Here, we have studied in detail the mechanisms of structural transitions between all three phases of Al2SiO5 – kyanite-andalusite, andalusite-sillimanite and kyanite-sillimanite at the pressures of 0 and 10 GPa. The phase transition pathways with the lowest energy barriers are found by constructing a number of geometrically likeliest pathways and optimizing them using the variable-cell nudged elastic band method (VCNEB). We have analyzed the structural changes along the obtained lowest-energy pathways. These results have provided insights into the nature of structural relationships between Al2SiO5 polymorphs, their coexistence with each other and their transformation pathways. In particular, we confirm that phase transition barriers are very high, which allows these phases to coexist during geological timescales – thus serving as geothermobarometers.

Translated title of the contributionMechanisms of phase transitions between Al2SiO5 polymorphs
Original languageRussian
Pages (from-to)79-91
Number of pages13
JournalZapiski Rossiiskogo Mineralogicheskogo Obshchestva
Volume150
Issue number5
DOIs
Publication statusPublished - 2021

Fingerprint

Dive into the research topics of 'Mechanisms of phase transitions between Al2SiO5 polymorphs'. Together they form a unique fingerprint.

Cite this