Synthese und Hochdruckverhalten quaternärer Chalkogenidhalogenide M2M′X3Y (M = Zn, Cd; M′ = Al, Ga, In; X = Se, Te; Y = CI, Br, I) / Synthesis and High-Pressure Behaviour of Quaternary Chalcogenide Halides M2M′X3Y (M = Zn, Cd; M′ = Al, Ga, In; X = Se, Te; Y = Cl, Br, I)

1988 ◽  
Vol 43 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Klaus-Jürgen Range ◽  
Karin Handrick
Keyword(s):  
High Pressure ◽  
Ambient Pressure ◽  
Type Structure ◽  
Zinc Blende ◽  
Binary Compounds ◽  
Gallium Compounds

Quaternary chalcogenide halides M2M′X3Y (M = Zn, Cd; M′ = Al, Ga, In; X = Se, Te; Y = Cl, Br, I) can be synthesized by heating stoichiometric amounts of the binary components MX. MY2, and M′2X3 in evacuated sealed quartz ampoules. In the case of aluminium and gallium compounds, a mixture of the M′ and X elements rather than the binary compounds has been used. The products are typical tetrahedral compounds, crystallizing with either the defect wurtzite-type or the defect zinc-blende-type structure. At 25 kbar, and 1400 °C, Cd2InSe3Cl, Cd2InSe3Br, and Cd2InSe3I transform from the defect wurtzite-type structure to quenchable high-pressure phases with defect NaCl-type structure. The retransformation to the ambient-pressure phases proceeds via intermediates having the defect zinc-blende-type structure. Some aspects of the apparent non-stoichiometry in the high-pressure phases are discussed

scholarly journals High-Pressure Synthesis of Non-Stoichiometric LixWO3 (0.5 ≤ x ≤ 1.0) with LiNbO3 Structure

Inorganics ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 63
Author(s):  
Kohdai Ishida ◽  
Yuya Ikeuchi ◽  
Cédric Tassel ◽  
Hiroshi Takatsu ◽  
Craig M. Brown ◽  
...  
Keyword(s):  
High Pressure ◽  
Perovskite Phase ◽  
Ambient Pressure ◽  
Tungsten Bronze ◽  
Type Structure ◽  
High Pressure Synthesis ◽  
Phase 0 ◽  
Pressure Synthesis ◽  
Octahedral Tilting ◽  
Recent Attention

Compounds with the LiNbO3-type structure are important for a variety of applications, such as piezoelectric sensors, while recent attention has been paid to magnetic and electronic properties. However, all the materials reported are stoichiometric. This work reports on the high-pressure synthesis of lithium tungsten bronze LixWO3 with the LiNbO3-type structure, with a substantial non-stoichiometry (0.5 ≤ x ≤ 1). Li0.8WO3 exhibit a metallic conductivity. This phase is related to an ambient-pressure perovskite phase (0 ≤ x ≤ 0.5) by the octahedral tilting switching between a−a−a− and a+a+a+.

Structural relationships between cations and alloys; an equivalence between oxidation and pressure

2001 ◽  
Vol 58 (1) ◽  
pp. 38-51 ◽  
Author(s):  
Angel Vegas ◽  
Martin Jansen
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
General Principle ◽  
Physical Meaning ◽  
Ambient Pressure ◽  
Ambient Conditions ◽  
Ionic Model ◽  
Structural Relationships ◽  
Structural Identity ◽  
Binary Compounds

More than 100 examples are provided of the structural identity between the cation arrays in oxides and their corresponding alloys (binary compounds). Halides and halogenates, sulfides and sulfites and/or sulfates, selenides and selenates, phosphides and phosphates show this behaviour. In some cases, the structure of the cation subarray corresponds to the structure of the alloy at ambient conditions, but in other cases, cations stabilize structures which correspond to those of the high-pressure phases of the alloy, from which an analogy between the insertion of oxygen and the application of pressure can be established. In this last case, the oxides show polymorphism with temperature and when heated, the structure of the ambient pressure of the alloy is recovered as if heating would compensate the effect of pressure. From the results reported here, it is concluded that cations do not seem to be either the isolated entities, predicted by the ionic model, which occupy interstices of an oxygen matrix, or they arrange in a more or less arbitrary way, but they try to reproduce the structure of their corresponding alloy. Many of the phase transitions and the polymorphism exhibited by the oxides described here are better explained when they are considered as formed by previous entities which are the alloys. Oxides should be considered as `real stuffed alloys'. These features do not seem to be casual, but they obey a general principle: Cations recognize themselves in spite of being embedded in an oxygen bulk. The nature and the physical meaning of this recognition are problems which remain unsolved.

Formation of PbCl2-type AHF (A = Ca, Sr, Ba) with Partial Anion Order at High Pressure

2021 ◽  
Author(s):  
Yumi Tsuchiya ◽  
Zefeng Wei ◽  
Thibault Broux ◽  
Cédric Tassel ◽  
Hiroki Ubukata ◽  
...  
Keyword(s):  
High Pressure ◽  
Metal Hydride ◽  
Alkaline Earth ◽  
Ambient Pressure ◽  
Earth Metal ◽  
Type Structure ◽  
Alkaline Earth Metal ◽  
Fluorite Type

The high-pressure structures of alkaline earth metal hydride-fluorides AHF (A = Ca, Sr, Ba) were investigated up to 8 GPa. While AHF adopts the fluorite-type structure (Fm-3m) at ambient pressure...

scholarly journals Study on the Phase Selection and Debye Temperature of Hyper-Peritectic Al-Ni Alloy under High Pressure

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
Xiaohong Wang ◽  
Zhipeng Chen ◽  
Duo Dong ◽  
Dongdong Zhu ◽  
Hongwei Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Ambient Pressure ◽  
Competitive Growth ◽  
Phase Selection ◽  
Debye Temperatures ◽  
Ni Alloy ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity ◽  
New Phase ◽  
Selection Of

The phase selection of hyper-peritectic Al-47wt.%Ni alloy solidified under different pressures was investigated. The results show that Al3Ni2 and Al3Ni phases coexist at ambient pressure, while another new phase α-Al exists simultaneously when solidified at high pressure. Based on the competitive growth theory of dendrite, a kinetic stabilization of metastable peritectic phases with respect to stable ones is predicted for different solidification pressures. It demonstrates that Al3Ni2 phase nucleates and grows directly from the undercooled liquid. Meanwhile, the Debye temperatures of Al-47wt.%Ni alloy that fabricated at different pressures were also calculated using the low temperature heat capacity curve.

scholarly journals Multianvil High-Pressure/High-Temperature Synthesis and Characterization of multiferroic HP-Co3TeO6

2021 ◽  
Author(s):  
Gunter Heymann ◽  
Elisabeth Selb ◽  
Toni Buttlar ◽  
Oliver Janka ◽  
Martina Tribus ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Type Structure ◽  
Synthesis And Characterization ◽  
Temperature Synthesis ◽  
Space Group ◽  
Crystal System ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

By high-pressure/high-temperature multianvil synthesis a new high-pressure (HP) phase of Co3TeO6 was obtained. The compound crystallizes in the acentric trigonal crystal system of the Ni3TeO6-type structure with space group R3...

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