scholarly journals High pressure phase transformation of jadeite and stability of NaAlSiO4with calcium-ferrite type structure in the lower mantle conditions

2000 ◽  
Vol 27 (14) ◽  
pp. 2025-2028 ◽  
Author(s):  
Faramarz Tutti ◽  
Leonid S. Dubrovinsky ◽  
Surendra K. Saxena
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Lower Mantle ◽  
High Pressure Phase ◽  
Type Structure ◽  
Calcium Ferrite ◽  
Pressure Phase

High-pressure phase transformation of BeGa2O4

1993 ◽  
Vol 8 (7) ◽  
pp. 1721-1727 ◽  
Author(s):  
K. Nakamura ◽  
M. Machida ◽  
M.E. Brito ◽  
H. Tabata
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Elevated Temperatures ◽  
High Pressure Phase ◽  
Type Structure ◽  
Temperature Phase ◽  
Temperature Ranges ◽  
The Stability ◽  
New Phase ◽  
Pressure Phase

High-pressure phase transformation of beryllium gallium oxide (BeGa2O4) has been studied. Applying high pressure at elevated temperatures to the original hexagonal BeGa2O4 (β–Si3N4-type structure), a high-pressure modification with orthorhombic structure (olivine-type structure) was obtained, i.e., o-BeGa2O4. Lattice parameters of the new phase were determined to be a = 0.5698, b = 0.9759, and c = 0.4551 nm. The pressure and temperature ranges where the high-pressure phase was observed are 3.5 to 7.5 GPa and 800 to 1600 °C, respectively. A tentative pressure-temperature phase diagram for BeGa2O4 was proposed. Transformation is not straightforward; decomposition of the original phase into single oxides and their recombination to form o-BeGa2O4 are necessary. This process seems to apply in both ways, formation and decomposition of the high-pressure phase. The stability of the high-pressure phase is explained in terms of the total molar volume for the phase, the result of summing up molar volumes of constituent compounds. This is the first known report on transformation of β–Si3N4-type structure into a denser structure.

scholarly journals High pressure phase transformation in iron under fast compression

2009 ◽  
Vol 95 (24) ◽  
pp. 241911 ◽  
Author(s):  
Marina Bastea ◽  
Sorin Bastea ◽  
Richard Becker
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
High Pressure Phase ◽  
Pressure Phase

High-pressure phase transformation of oriented CdSb single crystals

2005 ◽  
Vol 41 (3) ◽  
pp. 217-219 ◽  
Author(s):  
A. Yu. Mollaev ◽  
R. K. Arslanov ◽  
R. G. Dzhamamedov ◽  
S. F. Marenkin ◽  
S. A. Varnavskii
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Single Crystals ◽  
High Pressure Phase ◽  
Pressure Phase

Irreversible high pressure phase transformation of onion-like carbon due to shell confinement

2020 ◽  
Vol 107 ◽  
pp. 107908
Author(s):  
Dmitry S. Lugvishchuk ◽  
Edward B. Mitberg ◽  
Boris A. Kulnitskiy ◽  
Elena A. Skryleva ◽  
Yury N. Parkhomenko ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
High Pressure Phase ◽  
Pressure Phase

High-Pressure Phase Transformation of Cobalt Monoxide Due to Electronic Transition

1999 ◽  
Vol 38 (Part 2, No. 1A/B) ◽  
pp. L7-L9 ◽  
Author(s):  
Yuichi Noguchi ◽  
Toshiyuki Atou ◽  
Tadashi Kondo ◽  
Takehiko Yagi ◽  
Yasuhiko Syono
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Electronic Transition ◽  
High Pressure Phase ◽  
Pressure Phase

Studying the Temperature Effect During the High-Pressure Phase Transformation of Silicon via Indentations

2012 ◽  
Author(s):  
Deepak Ravindra ◽  
John Patten ◽  
Muralidhar K. Ghantasala
Keyword(s):  
High Pressure ◽  
Phase Transformation ◽  
Temperature Effect ◽  
Brittle Material ◽  
Material Removal ◽  
Thermal Softening ◽  
High Pressure Phase ◽  
Ductile Mode ◽  
Indentation Tests ◽  
Pressure Phase

Micro-laser assisted machining (μ-LAM) is a novel micro/nano machining technique developed for ductile mode machining of ceramics and semiconductors. Ductile mode material removal is possible in a nominally brittle material due to the high-pressure phase transformation (HPPT) phenomenon during the machining process. This study isolates the pressure and temperature effect in the μ-LAM process. The μ-LAM process is unique whereby the pressure and temperature effect occur concurrently leading to the material removal process. The effect of temperature and thermal softening is studied via indentation tests using a cutting tool. In the precisely controlled indentation tests, laser heating is applied at various stages to determine the phase (i.e. atmospheric Si-I phase or high pressure phases that benefits most from the thermal softening effect. The indentation depths are measured and compared for each condition to identify the enhanced ductility of the nominally brittle material caused by the laser irradiation.

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