Observation of 9-Fold Coordinated Amorphous TiO 2 at High Pressure

Knowledge of the structure in amorphous dioxides is important in many fields of science and engineering. Here we report new experimental results of high-pressure polyamorphism in amorphous TiO (a-TiO ). Our data show that the Ti coordination number (CN) increases from 7.2 ± 0.3 at ∼16 GPa to 8.8 ± 0...

Full description

Saved in:
Bibliographic Details
Published in:The journal of physical chemistry letters 2020-01, Vol.11 (2), p.374-379
Main Authors: Shu, Yu, Kono, Yoshio, Ohira, Itaru, Li, Quanjun, Hrubiak, Rostislav, Park, Changyong, Kenney-Benson, Curtis, Wang, Yanbin, Shen, Guoyin
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Knowledge of the structure in amorphous dioxides is important in many fields of science and engineering. Here we report new experimental results of high-pressure polyamorphism in amorphous TiO (a-TiO ). Our data show that the Ti coordination number (CN) increases from 7.2 ± 0.3 at ∼16 GPa to 8.8 ± 0.3 at ∼70 GPa and finally reaches a plateau at 8.9 ± 0.3 at ≲86 GPa. The evolution of the structural changes under pressure is rationalized by the ratio (γ) of the ionic radius of Ti to that of O. It appears that the CN ≈ 9 plateau correlates with the two 9-fold coordinated polymorphs (cotunnite, Fe P) with different γ values. This CN-γ relationship is compared with those of a-SiO and a-GeO , displaying remarkably consistent behavior between CN and γ. The unified CN-γ relationship may be generally used to predict the compression behavior of amorphous AO compounds under extreme conditions.
ISSN:1948-7185
1948-7185
DOI:10.1021/acs.jpclett.9b03378