Equilibrium Phase Diagrams for Analysis of the Oxidation of III-V Compound Semiconductors

1989 ◽  
Vol 148 ◽  
Author(s):  
G. P. Schwartz
Keyword(s):  
High Pressure ◽  
Phase Diagrams ◽  
Equilibrium Phase ◽  
Compound Semiconductors ◽  
Growth Conditions ◽  
Pressure Oxidation ◽  
Recent Interest ◽  
Equilibrium Growth ◽  
Thermodynamic Factors

ABSTRACTThe phases which result from the oxidation of III-V compound semiconductors can be predicted from a knowledge of the condensed phase portion of their equilibrium phase diagrams. Examples will be shown for arsenides, antimonides, and phosphides. Use of these diagrams explicitly presumes equilibrium growth conditions, and that assumption often fails. In such cases kinetic rather than thermodynamic factors dominate the determination of the observed phases. Examples of this phenomenon for anodic oxidation will be presented. Recent interest in high pressure oxidation conditions as a means of alleviating kinetic limitations will be discussed for InP. The phase diagrams can also be used to predict interfacial reactions under certain conditions and data for GaAs will serve to illustrate this point.

Design and Analysis of a High Pressure Apparatus

1980 ◽  
Vol 102 (3) ◽  
pp. 633-640
Author(s):  
K. C. Rolle ◽  
J. N. Crisp ◽  
A. N. Palazotto
Keyword(s):  
Finite Element ◽  
High Pressure ◽  
Phase Diagrams ◽  
High Pressures ◽  
Equilibrium Phase ◽  
Original Design ◽  
Piston Displacement ◽  
Crude Analysis ◽  
High Pressure Apparatus

In the determination of equilibrium phase diagrams, i.e., pressure volume-temperature relations for lubricants at pressures up to 2800 MPa and temperatures of 378K, one must carry out a highly sophisticated design of a high pressure apparatus. In 1935 Bridgman designed a piston-displacement device and measured the compressibility of numerous materials at high pressures. However, in order to obtain accurate equilibrium phase diagrams for lubricants, Bridgman’s relatively crude analysis must be considerably refined. The authors have extended this original design using finite element techniques to accurately correct pertinent measurements which are in turn incorporated into the expressions used in determining the pressure-volume temperature relations of lubricants.

Electrochemical Determination of Phase Diagrams and Thermodynamic Data of Multi-Component Systems

1980 ◽  
Vol 35 (4) ◽  
pp. 381-388 ◽  
Author(s):  
W. Weppner ◽  
Chen Li-chuan ◽  
W. Piekarczyk
Keyword(s):  
Phase Diagrams ◽  
Coulometric Titration ◽  
Equilibrium Phase ◽  
Cell Voltage ◽  
Electrochemical Determination ◽  
Specific Cell ◽  
Gibbs Energies ◽  
Component Systems ◽  
Titration Technique

Abstract The coulometric titration technique is extended to treat general cases of systems of any number of components. Complete equilibrium phase diagrams and thermodynamic properties are obtained from readily and precisely measurable electrical quantities, employing only a small number of samples. General equations are derived which directly relate the cell voltage to the standard Gibbs energies, enthalpies and entropies of formation of all phases involved without the necessity of considering specific cell reactions. The application of the technique to the ternary system Cu-Ge-O is demonstrated.

Experimental determination of solid-liquid-liquid equilibrium phase diagrams

AIChE Journal ◽  
2007 ◽  
Vol 53 (6) ◽  
pp. 1608-1619 ◽  
Author(s):  
Sau M. Lai ◽  
Mai Y. Yuen ◽  
Leo K. S. Siu ◽  
Ka M. Ng ◽  
Christianto Wibowo
Keyword(s):  
Experimental Determination ◽  
Phase Diagrams ◽  
Equilibrium Phase ◽  
Liquid Equilibrium ◽  
Solid Liquid

Determination of the phase diagrams of the Cd-Sn(0.2)-Zn ternary system at high pressure

1992 ◽  
Vol 187 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Lizhu Song ◽  
Hua Yang ◽  
Muyu Zhao ◽  
Zhongyi Shen ◽  
Yong Liu
Keyword(s):  
High Pressure ◽  
Ternary System ◽  
Phase Diagrams

scholarly journals Raman spectroscopy of high-pressure phases in shocked L6 chondrite NWA 5011

2019 ◽  
Vol 64 (8) ◽  
pp. 848-858
Author(s):  
K. D. Litasov ◽  
D. D. Badyukov
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Phase Diagrams ◽  
Equilibrium Phase ◽  
Calcium Ferrite ◽  
Impact Melt ◽  
Shock Process ◽  
The Impact ◽  
First Time ◽  
Late Stages

In the paper we present results of studies of thick shock melt veins in NWA 5011 L6 chondrite. The veins contain a wide variety of high-pressure phases that correspond to contrast values of pressure-temperature parameters on equilibrium phase diagrams. Olivine was transformed to ringwoodite and wadsleyte, orthopyroxene to majorite, akimotoite, and bridgmanite glass, maskelenite is converted to jadeite (+SiO2) and lingunite, apatite to tuite, and chromite to the phase with the calcium ferrite (mCF-FeCr2O4) structure. ) The peak PT shock parameters for NWA 5011 seem highest among the ones for other shocked chondrites according to wide occurrence of lingunite and bridgmanite glass and are considerable higher than 25 GPa and 2500 K. Akimotoite crystals in a quenched matrix of shock melt veins were found for the first time. Probably, they initially crystallized as bridgmanite, since akimotoite is not a liquidus phase in related systems. Plagioclase-chromite aggregates have been established, which characterize the late stages of the shock process and are formed during successive crystallization from isolated pockets of the impact melt.

Sign in / Sign up

Export Citation Format

Share Document