Quenchable amorphous glass-like material from VF3. Issue 8 (10th February 2021)

• Record Type: Journal Article
• Authors: Sereika, Raimundas; Kim, Sooran; Nakagawa, Takeshi; Ishii, Hirofumi; Ding, Yang; Mao, Ho-kwang
• Is Part Of: Dalton transactions. Volume 50:Issue 8(2021)
• Page Start: 3005
• Page End: 3010
• Publication Date: 2021-02-10
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1dt00033k
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : This study shows that metal trifluorides are appealing group of compounds to search and investigate pressure-induced amorpization. Abstract : The quite simple but relatively stable VF3 -type compounds are known to be of major interest due to their building blocks – octahedra that are extremely important in perovskites as well. Here, we show that the VF6 octahedron in VF3 varies over a fairly wide pressure range (0–50 GPa), maintaining undisturbed rhombohedral crystal symmetry. Half of this pressure, VF6 rotates easily while the other undergoes strong uniaxial deformation in a "super-dense" condition. The congested sphere packing ultimately does not endure and drives the material to amorphize. We observed that the amorphous state could be quenched and acquire a transparent glass-like appearance when unloaded to ambient conditions. Dramatic, pressure-induced changes are clarified by phonon dispersion curves with the imaginary phonon mode, the so-called phonon soft mode, which indicates the structural instability. The distortion of the VF6 octahedra is attributed to the distinctive amorphization that could be further searched for throughout the whole almost identical VF3 -type series providing metal trifluorides of various amorphous species.