Pressure-induced amorphization of the Y3Ga5O12 garnet studied to 1 Mbar

• Published in: Journal of alloys and compounds 2020-07, Vol.830, p.154678, Article 154678
• Main Authors: Monteseguro, V., Ruiz-Fuertes, J., Berkowski, M., Garbarino, G.
• Format: Article
• Language: English
• Subjects: Amorphization; Bulk modulus; Compressibility; Crystal structure; Garnets; Mathematical analysis; Microbeams; Nanocrystals; Pressure; Regularization; Single crystals; Synchrotron radiation; Unit cell; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.154678

We use micro-beam synchrotron x-ray diffraction to study the pressure-induced amorphization of nano-sized and single crystals of Y3Ga5O12 up to pressures exceeding 1 Mbar in static compression. The abrupt pressure-induced amorphization found for both 56 nm and bulk micrometric crystals at around 76 GPa independently of the pressure transmitting medium employed demonstrates its intrinsic nature, previously predicted at 79 GPa by ab initio calculations. The single crystal structural solution at 50 GPa shows that the contraction of the unit-cell, mostly accommodated by the compressible YO8 dodecahedra, gives rise to a regularization and tilting increase of the GaO6 polyhedra with the Y–O-Ga angle changing from 104.84° to 102.34° in 50 GPa. We obtain a bulk modulus of 178(3) GPa for the single crystal and 172(3) GPa for the nanocrystals in excellent agreement with previous calculations. •Micro-beam synchrotron x-ray diffraction up to 1 Mbar.•Comparative simultaneously 56 nm and bulk micrometric Y3Ga5O12 garnet crystals.•Pressure-induced amorphization does not depend neither pressure-transmitting medium or crystal size.•Independently of the chemical formula garnets relay most of their compression on that of their dodecahedra.