scholarly journals Эффекты легирования сульфида свинца серебром на решеточных и оптических свойствах твердых растворов Pb-=SUB=-1-x-=/SUB=-Ag-=SUB=-x-=/SUB=-S

2019 ◽  
Vol 53 (12) ◽  
pp. 1675
Author(s):  
С.И. Садовников
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Single Phase ◽  
Coefficient Of Thermal Expansion ◽  
Relative Content ◽  
Atomic Vibrations ◽  
Metal Sublattice ◽  
First Time ◽  
Linear Compressibility ◽  
Silver Atoms

Single-phase limited cubic solid solutions Pb1-xAgxS based on PbS with a metal sublattice alloyed with silver are obtained. The maximum relative content of silver in solid solutions Pb1-xAgxS reaches x = 0.15. For the first time the thermal expansion of semiconductor solid solutions Pb1-xAgxS was measured by dilatometry method in the temperature range 295-580 K. Substitution of lead atoms by silver atoms in Pb1-xAgxS leads to a decrease in the coefficient of thermal expansion associated with a change in the anharmonicity of atomic vibrations and a weak increase in the elastic properties. For single-crystal particles PbS and solid solutions Pb1-xAgxS, spatial distributions of the elastic modulus E, Poisson's ratio , and linear compressibility  as a function of the direction (hkl) are found. The reflection spectra of the synthesized powders PbS, Ag2S and Pb1-xAgxS are measured and it is shown that the replacement of lead with silver in PbS is accompanied by an increase in the width of the band gap.

scholarly journals Тепловое расширение ограниченных полупроводниковых твердых растворов Ag-=SUB=-x-=/SUB=-Pb-=SUB=-1-x-=/SUB=-S

2019 ◽  
Vol 61 (6) ◽  
pp. 1060
Author(s):  
С.И. Садовников
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Lead Acetate ◽  
Single Phase ◽  
Silver Content ◽  
Small Decrease ◽  
Stabilizing Agents ◽  
Sulfidizing Agent ◽  
First Time ◽  
Silver Atoms

Single-phase powders of AgxPb1-xS cubic solid solutions with a maximum relative silver content up to x = 0.12 were synthesized from aqueous solutions of lead acetate and silver nitrate in the presence of a sulfidizing agent, complexing and stabilizing agents. Thermal expansion of synthesized semiconductor solid solutions AgxPb1-xS was measured for the first time by dilatometry in the temperature range of 295-580 K. It is shown that the replacement of lead atoms by silver atoms in AgxPb1-xS leads to a small decrease in the thermal expansion coefficient associated with a change in the anharmonicity of atomic oscillations.

Very high or close to zero thermal expansion by the variation of the Sr/Ba ratio in Ba1−xSrxZn2Si2O7 – solid solutions

2016 ◽  
Vol 45 (11) ◽  
pp. 4888-4895 ◽  
Author(s):  
Christian Thieme ◽  
Christian Rüssel
Keyword(s):  
Thermal Expansion ◽  
Solid Solutions ◽  
Coefficient Of Thermal Expansion ◽  
Positive Coefficient ◽  
Negative Coefficient ◽  
Very High

The compound BaZn2Si2O7 shows a highly positive coefficient of thermal expansion, while replacement of more than 10% of Ba2+ by Sr2+ results in a negative coefficient of thermal expansion.

scholarly journals Тепловое расширение кристаллов Pb-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te

2021 ◽  
Vol 55 (12) ◽  
pp. 1216
Author(s):  
М.К. Шаров
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Solid Solutions ◽  
Coefficient Of Thermal Expansion ◽  
Cadmium Content ◽  
Lattice Period ◽  
Linear Coefficient ◽  
X Ray ◽  
Temperature Range

The values of the lattice period and the linear coefficient of thermal expansion (alfa) of Pb1-xCdxTe solid solutions are determined depending on the cadmium content and temperature using high-temperature X-ray diffractometry. Аn increase in the concentration of cadmium in Pb1-xCdxTe in the range x = 0.02–0.08 leads to a significant increase in the linear coefficient of thermal expansion. A change in temperature range T = 293–673 K leads to decrease in the linear coefficient of thermal expansion. Besides, an increase in temperature does not affect the value alfa of the undoped PbTe in the indicated temperature range.

scholarly journals Modelling the coefficient of thermal expansion in graphite crystals: implications of lattice strain due to irradiation and pressure

2018 ◽  
Vol 474 (2218) ◽  
pp. 20180075 ◽  
Author(s):  
Barry Marsden ◽  
Andrew Mummery ◽  
Paul Mummery
Keyword(s):  
Thermal Expansion ◽  
Input Data ◽  
Lattice Spacing ◽  
Lattice Strain ◽  
Coefficient Of Thermal Expansion ◽  
Pyrolytic Graphite ◽  
Theoretical Models ◽  
Nuclear Graphite ◽  
First Time ◽  
Insight Into

Theoretical models for the coefficient of thermal expansion (CTE) first proposed in the 1970s are expanded upon, allowing them, for the first time, to be implemented over a wide temperature range. The models are of interest because they predict the effects of the changes in the crystal lattice spacing and crystallite modulus on the CTE. Hence, they can in turn be used to investigate the influence of pressure and irradiation on the CTE. To date, typographical and mathematical errors and incomplete or conflicting assumptions between the various papers had made the complex mathematical formulations difficult, if not impossible, to follow and apply. This paper has two main aims: firstly to revisit and review the CTE models, correcting the errors and compiling and updating various input data, secondly to use the revised models to investigate the effect of loading and irradiation on the CTE. In particular, the models have been applied to data for natural and highly orientated pyrolytic graphite and compared with experimental data, giving an insight into the influence of temperature, loading and irradiation on both single crystal and polycrystalline graphite. The findings lend credence to postulated microstructural mechanisms attributed to the in-reactor behaviour of nuclear graphite, which finds a wide use in predictive multiscale modelling.

Calculation of the linear coefficient of thermal expansion of multi-element, single-phase metal alloys from the first principles

2021 ◽  
Vol 2021 (2) ◽  
pp. 10-18
Author(s):  
A. A. Khachatrian ◽  
Keyword(s):  
Thermal Expansion ◽  
Melting Point ◽  
First Principles ◽  
Single Phase ◽  
Coefficient Of Thermal Expansion ◽  
Interatomic Interaction ◽  
Metal Alloys ◽  
Potential Force ◽  
Linear Coefficient ◽  
Quasiharmonic Approximation

One of the possible ways to calculate the coefficient of thermal expansion is a method based on determining the dependence of the total energy of the electron-ion system on the parameters of the crystal lattice at different temperatures. There is a relationship between the calculated values of the linear coefficients of thermal expansion and the melting point of the material. For metals and multi-element single-phase alloys, the dependence of the function V = α·Tmax on the parameter T/Tmax (α — the linear coefficients of thermal expansion, Tmax — melting point of the material) is obtained from the first principles, which has the same form for all single-phase multi-element metal alloys and is presented analytically. Using the method of pseudopotential and quasiharmonic approximation, the linear coefficients of thermal expansion of multi-element metal alloys are calculated. The temperature dependence of the coefficient of thermal expansion, after approximating the results of the computational experiment, is presented in analytical form. The results were compared with known tabular data. To confirm the reliability of the model, the calculation was performed for a number of pure metals. The consistency of the calculated and experimental data on the coefficient of thermal expansion of single-phase alloys calculated from the first principles is observed. There is a relationship between the calculated values of the linear coefficients of thermal expansion and the melting point of the material. For metals and multi-element single-phase alloys, the dependence of the function V = α·Tmax on the parameter T/ Tmax (α — the linear coefficients of thermal expansion, Tmax — melting point of the material) is obtained from the first principles, which has the same form for all single-phase multi-element metal alloys and is presented analytically. Keywords: Electron-ion system energy, interatomic interaction potential, force constants, quasiharmonic approximation, coefficient of thermal expansion.

Thermal Expansion of Nanostructured Solid Solutions of Lead and Silver Sulfides

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940061 ◽  
Author(s):  
S. I. Sadovnikov
Keyword(s):  
Thermal Expansion ◽  
Aqueous Solutions ◽  
Silver Nitrate ◽  
Solid Solutions ◽  
Lead Acetate ◽  
Stabilizing Agent ◽  
First Time

Cubic solid solutions AgxPb[Formula: see text]S are synthesized by chemical co-deposition from aqueous solutions of lead acetate and silver nitrate in the presence of a sulfidizing, complexing and stabilizing agent. For the first time, thermal expansion of the synthesized semiconductor solid solutions AgxPb[Formula: see text]S is determined.

NILO ALLOY 36

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Constant Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Iron Nickel

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..

UNISPAN LR35

Alloy Digest ◽  
1971 ◽  
Vol 20 (1) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Operational Level

Abstract UNISPAN LR35 offers the lowest coefficient of thermal expansion of any alloy now available. It is a low residual modification of UNISPAN 36 for fully achieving the demanding operational level of precision equipment. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: Fe-46. Producer or source: Cyclops Corporation.

DELTALLOY 4032

Alloy Digest ◽  
1998 ◽  
Vol 47 (4) ◽  
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Surface Finish ◽  
Coefficient Of Thermal Expansion ◽  
Single Point ◽  
High Strength ◽  
Corrosion And Wear

Abstract Deltalloy 4032 has good machinability and drilling characteristics when using single-point or multispindle screw machines and an excellent surface finish using polycrystalline or carbide tooling. The alloy demonstrates superior wear resistance and may eliminate the need for hard coat anodizing. Deltalloy 4032 is characterized by high strength and a low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion and wear resistance as well as machining and surface treatment. Filing Code: AL-347. Producer or source: ALCOA Wire, Rod & Bar Division.

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