The stability and equation of state for the cotunnite phase of TiO2 up to 70 GPa

@article{NishioHamane2010TheSA,
  title={The stability and equation of state for the cotunnite phase of TiO2 up to 70 GPa},
  author={Daisuke Nishio‐Hamane and Asa Shimizu and Ritsuko Nakahira and Ken Niwa and Asami Sano-Furukawa and Taku Okada and Takehiko Yagi and Takumi Kikegawa},
  journal={Physics and Chemistry of Minerals},
  year={2010},
  volume={37},
  pages={129-136}
}
The stability and equation of state for the cotunnite phase in TiO2 were investigated up to a pressure of about 70 GPa by high-pressure in situ X-ray diffraction measurements using a laser-heated diamond anvil cell. The transition sequence under high pressure was rutile → α-PbO2 phase → baddeleyite phase → OI phase → cotunnite phase with increasing pressure. The cotunnite phase was the most stable phase at pressures from 40 GPa to at least 70 GPa. The equation of state parameters for the… 

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References

SHOWING 1-10 OF 24 REFERENCES

The equation of state of CaSiO3 perovskite to 108 GPa at 300 K

The equation of state of platinum to 660 GPa (6. 6 Mbar)

Platinum metal was shock compressed to 660 GPa using a two‐stage light‐gas gun to qualify this material as an ultrahigh‐pressure standard for both dynamic and static experiments. The shock velocity

First-principles calculations of the phase stability of TiO2

First-principles calculations of the crystal structures, bulk moduli, and relative stabilities of seven known and hypothetical TiO2 polymorphs ~anatase, rutile, columbite, baddeleyite, cotunnite,

High-pressure polymorphs of anatase TiO 2

The equation of state of anatase TiO 2 has been determined experimentally—using polycrystalline as well as single-crystal material—and compared with theoretical calculations using the ab initio

Ab initio study of the elastic properties of single and polycrystal TiO(2), ZrO(2) and HfO(2) in the cotunnite structure.

It is found that C(11), C(22) and C(33) elastic constants of hafnia and zirconia show increased strength with respect to the experimental values of the normal phase, P 2(1)/c, and this fact increases the compound anisotropy as well as its ductile behavior.

Phase transitions and equations of state for the sodium halides: NaF NaCl, NaBr, and NaI

Phase changes and equations of state of four sodium halides, NaF, NaCl, NaBr, and NaI, have been studied up to ∼60 GPa at room temperature with the use of a diamond anvil cell. NaF and NaCl transform

High-pressure behavior of TiO 2 as determined by experiment and theory

Using high-resolution synchrotron x-ray powder diffraction we have investigated the structural phase transitions and equations of state of titanium dioxide (TiO{sub 2}) under high pressure before and

High-pressure structural phase transitions in TiO2 and synthesis of the hardest known oxide

Despite great technological importance and many investigations, a material with a measured hardness comparable to that of diamond or cubic boron nitride has yet to be identified. Our combined

High-pressure phases of ZrO2 : An ab initio constant-pressure study

The high-pressure behavior of ${\text{ZrO}}_{2}$ is studied using an ab initio constant-pressure technique up to 140 GPa. Two high-pressure phases of ${\text{ZrO}}_{2}$ are predicted through