The Use of Superlattice Reactants in The Synthesis of Ternary CU‐NB‐SE Compounds

1994 ◽  
Vol 346 ◽  
Author(s):  
Marc D. Hornbostel ◽  
Masafumi Fukuto ◽  
David C. Johnson
Keyword(s):  
Low Temperature ◽  
Thermodynamic Stability ◽  
Binary Systems ◽  
Cluster Compounds ◽  
Reaction Intermediates ◽  
Ternary Compounds ◽  
Controlled Crystallization ◽  
Binary Compounds

ABSTRACTThe low temperature interdiffusion of superlattice reactants of the binary systems niobium‐selenium and copper‐selenium and the ternary copper‐niobium‐selenium were explored to synthesize amorphous reaction intermediates. Controlled crystallization of this intermediate, which depends upon nucleation energetics rather than the thermodynamic stability of the final product, was used as we attempted to prepare ternary niobium cluster compounds. We present data demonstrating the ability to prepare amorphous ternary intermediates without the formation of crystalline binary compounds as reaction intermediates. Crystallization of the amorphous intermediate resulted in the formation of known ternary compounds directly, also without the formation of binary compounds.

Synthesis of New Thermoelectric Materials Using Modulated Elementary Reactants

1998 ◽  
Vol 545 ◽  
Author(s):  
Heike Sellinschegg ◽  
Joshua R. Williams ◽  
Steven P. Maxwell ◽  
Douglas Sillars ◽  
David C. Johnson
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Low Temperature ◽  
Reaction Intermediates ◽  
Ternary Compounds ◽  
Low Temperature Annealing ◽  
Modulated Elemental Reactants ◽  
Ternary Metal ◽  
Elemental Reactants ◽  
Binary Compounds

AbstractModulated elemental reactants have been used to synthesize metastable ternary compounds with the skutterudite crystal structure. The initial reactants are made up of multiple repeats of a unit containing elemental layers of a ternary metal, iron or cobalt (or a combination of these two) and antimony. The elemental layers interdiffuse upon low temperature annealing and form amorphous reaction intermediates. In this paper we target the compounds PbxFe4−yCoySb12. On annealing at temperatures between 12° and 150° C (depending on the composition) crystallization of the skutterudite structure occurs. The compounds are only kinetically stable, decomposing into a mixture of binary compounds upon annealing past a temperature of about 600°C. Preliminary data for the Seebeck coefficient and the electrical conductivity was collected The thermoelectric properties of the lead cobalt antimony skutterudite - films were measured as a function of lead occupancy.

scholarly journals Isothermal section of the Ni-Mn-Sb ternary system at 773K

2019 ◽  
Vol 55 (2) ◽  
pp. 147-156 ◽  
Author(s):  
W.-Q. Ao ◽  
H.-Z. Yu ◽  
F.-L. Liu ◽  
F.-S. Liu ◽  
J.-Q. Li ◽  
...  
Keyword(s):  
Isothermal Section ◽  
Ternary System ◽  
Binary Systems ◽  
Type Structure ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
Heusler Compound ◽  
Space Group ◽  
Ternary Compounds ◽  
Binary Compounds

The isothermal section of the Ni-Mn-Sb ternary system at 773 K was measured by means of 117 alloys which were analyzed by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), and electron probe microanalysis (EPMA) techniques. The existence of 7 binary compounds, namely NiMn, Mn2Sb, MnSb, NiSb2, NiSb, Ni5Sb2, Ni3Sb and 2 ternary compounds, namely Ni2MnSb and NiMnSb were confirmed for this isothermal section. The four binary compounds Ni3Sb (Cu3Ti structure, Pmmn space group), Ni5Sb2 (Ni5Sb2-type structure, C2 space group), NiSb2 (FeS2-type structure, Pnnm space group) and Mn2Sb (Cu2Sb-type structure, P4/nmm space group) in the binary systems Ni-Sb and Mn-Sb were stoichiometric compounds, the homogeneity ranges of which were negligible. However the five single phases in the Ni-Mn system and the two binary compounds MnSb and NiSb showed more or less homogeneity ranges formed by substitution of Mn and Sb for Ni atom. The Heusler compound ? (Ni2MnSb) has L21-type ordered structure with space group Fm-3m, a = 0.6017 nm. And the crystal structure for the Half-Heusler compound ? (NiMnSb) is C1b-type (F-43m) with a = 0.5961 nm. The approximate homogeneity ranges of the two ternary compounds ? and ? at 773 K were investigated.

scholarly journals Climate Change and Refrigerants: Thermodynamic Properties of Low-GWP Fluids for Domestic Applications and Binary Systems for Low-Temperature Options

2020 ◽  
Vol 10 (6) ◽  
pp. 2014 ◽  
Author(s):  
Mariano Pierantozzi ◽  
Sebastiano Tomassetti ◽  
Giovanni Di Nicola
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Global Warming ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
Experimental Research ◽  
Binary Systems ◽  
Research Activity ◽  
Greenhouse Gasses ◽  
Low Global Warming Potential

The most commonly used refrigerants are potent greenhouse gasses that can contribute to climate change. Hydro-Fluoro-Olefins are low Global Warming Potential fluids. A summary of our experimental research activity on the thermodynamic properties of two environmentally friendly Hydro-Fluoro-Olefins, namely R1234yf and R1234ze(E), is reported. In particular, the measurements were performed with an isochoric apparatus and the apparatus specifically built to reach temperatures down to about 100 K. The data elaboration confirms the validity of the choice and that R1234yf and R1234ze(E) can be adopted in many domestic applications. Moreover, considering the reduction of the flammability issues of R1234yf and R1234ze(E), the properties of binary systems containing these fluids and carbon dioxide were analyzed. The presented mixtures could be very interesting for low-temperature applications such as cascade cycles.

The thermodynamic stability of three near-degenerate phases of platinum dioxide

2004 ◽  
Vol 848 ◽  
Author(s):  
Shuping Zhuo ◽  
Karl Sohlberg
Keyword(s):  
High Pressure ◽  
Fixed Point ◽  
Low Temperature ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Energy Surface ◽  
Stable Phase ◽  
Free Energies ◽  
Rutile Structure ◽  
Unstable Fixed Point

ABSTRACTThe thermodynamic stability of the three nearly energy degenerate crystal structures of PtO2 is studied here with first-principles-based calculations of their free energies. For P = 0 the α-(CdI2) structure is the thermodynamically stable phase at low temperature, while the β-(CaCl2) structure is stable at high pressure. The β'-(rutile) structure represents an unstable fixed point on the potential energy surface, or is possibly just barely bound. These results reconcile seemingly contradictory findings and answer longstanding questions about PtO2.

Synthesis of chalcopyrite-type and thiospinel minerals/materials by low temperature melts of xanthates

2018 ◽  
Vol 47 (27) ◽  
pp. 8870-8873 ◽  
Author(s):  
Malik Dilshad Khan ◽  
Ghulam Murtaza ◽  
Neerish Revaprasadu ◽  
Paul O'Brien
Keyword(s):  
Low Temperature ◽  
Efficient Synthesis ◽  
Ternary Compounds

Xanthate complexes are used in the low temperature atom efficient synthesis of some geological and technologically important ternary compounds.

scholarly journals Mesoporous Ce-Zr solid solutions supported Ni-based catalysts for low-temperature CO2 methanation by tuning the reaction intermediates

Fuel ◽  
2020 ◽  
Vol 282 ◽  
pp. 118813
Author(s):  
Leilei Xu ◽  
Xueying Wen ◽  
Mindong Chen ◽  
Chufei Lv ◽  
Yan Cui ◽  
...  
Keyword(s):  
Low Temperature ◽  
Solid Solutions ◽  
Reaction Intermediates ◽  
Co2 Methanation ◽  
Supported Ni

Low temperature properties of the ternary compounds CePt2B and CePt3B

2005 ◽  
Vol 17 (11) ◽  
pp. S905-S910 ◽  
Author(s):  
R Lackner ◽  
M Sieberer ◽  
H Michor ◽  
G Hilscher ◽  
E Bauer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ternary Compounds
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