The first-principles study of phase stability and crystal structure of cotunnite TiO2 under decompression
DONG Hai-kuan
QI Yi-hui
Abstract：Using GGA method based on the density-functional theory to calculate cotunnite anatase and ru-tile TiO2 . Firstly,The crystal structure of the three phases are optimized and the related parameters are ob-tained. The change curves of enthalpy along with the pressure are analyzed. It is found that the cotunnite struc-ture can directly change to anatase structure when the decompression to 2. 0 GPa. Secondly,it is obtained that bulk modulus B0 and equilibrium volumes V0 by fitting the third -order Birch -Murnaghan equation of state. And the fitting results very accord with experimental and other theoretical values. Finally,it is further discussed that The phase transformation behavior of cotunnite TiO2 by comparing the crystal structure,bulk modulus B0 and equilibrium volumes V0 change before and after the phase change. Meanwhile,we hope our results provide a the-oretical reference for related experimental research.
Keywords：the first principlesTiO2phase transitioncotunnite TiO2
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 36-40,90 )