scholarly journals Распад твердого раствора межузельного магния в кремнии

2019 ◽  
Vol 53 (3) ◽  
pp. 314
Author(s):  
В.Б. Шуман ◽  
А.Н. Лодыгин ◽  
Л.М. Порцель ◽  
А.А. Яковлева ◽  
Н.В. Абросимов ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Single Crystal ◽  
Diffusion Activation Energy ◽  
Practical Application ◽  
Float Zone ◽  
Sandwich Method ◽  
Kinetics Of ◽  
Diffusion Activation

AbstractThe decomposition of a solid solution of interstitial magnesium Mg_ i in silicon is studied. Float-Zone dislocation-free single-crystal n -Si with a resistivity of ~8 × 10^3 Ω cm and oxygen and carbon contents of ~5 × 10^14 cm^–3 and ~1 × 10^15 cm^–3 is used in the experiments. The samples are doped using the diffusion sandwich method at T =1100°C followed by quenching. Decomposition of the supersaturated Mg_ i solid solution is studied by observing the kinetics of increasing the resistivity of doped samples resulting from their annealing in the range T = 400–620°C. It is found that the decomposition is characterized by an activation energy of E _ a ≈ 1.6 eV, which is close to the previously determined diffusion activation energy of Mg_ i in silicon. It is also shown that Si:Mg exhibits stable properties at temperatures not exceeding 400°C, which is important for its possible practical application.

Study on the Drying Mechanism and Dynamics of Palygorskite

2011 ◽  
Vol 422 ◽  
pp. 501-504
Author(s):  
Jiang Quan Ma ◽  
Qing Ling Lu ◽  
Jun Hao Xia ◽  
Xiao Bin Gan ◽  
Chao Yao
Keyword(s):  
Activation Energy ◽  
Environmental Protection ◽  
Drying Kinetics ◽  
Diffusion Activation Energy ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Curves ◽  
Kinetics Of ◽  
Diffusion Activation

Palygorskite had large applications in chemical, environmental protection, medicine processes and so on. However, since the mineral limitations of natural palygorskite, both improving its quality and meeting the need of industry, palygorskite usually needs to be activated before using it. The influences of activation during the drying process were studied, as well as the drying kinetics of the non-activated of palygorskite. The results showed that the drying rate of palygorskite increased at first, and then came to a constant value, and kept that value for some time. After that, drying rate decreased with time going. Compared with drying curves of the non activated palygorskite, the samples made some changes after activation. The drying process of non activated palygorskite could be described as the equation of MR=exp(-ktn). The diffusion activation energy (E) of non activated palygorskite was equal to 17.14kJ•mol-1, former factors of Arrhenius was equal to 4.19×10-5 m2•s-1.

Study on the Drying Mechanism and Dynamics of Palygorskite

2013 ◽  
Vol 706-708 ◽  
pp. 456-459
Author(s):  
Shi Long Wang ◽  
Li Na Wang
Keyword(s):  
Activation Energy ◽  
Environmental Protection ◽  
Drying Kinetics ◽  
Diffusion Activation Energy ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Curves ◽  
Kinetics Of ◽  
Diffusion Activation

Palygorskite had large applications in chemical, environmental protection, medicine processes and so on. However, since the mineral limitations of natural palygorskite, both improving its quality and meeting the need of industry, palygorskite usually needs to be activated before using it. The influences of activation during the drying process were studied, as well as the drying kinetics of the non-activated of palygorskite. The results showed that the drying rate of palygorskite increased at first，and then came to a constant value, and kept that value for some time. After that, drying rate decreased with time going. Compared with drying curves of the non activated palygorskite, the samples made some changes after activation. The drying process of non activated palygorskite could be described as the equation of MR=exp(-ktn).The diffusion activation energy (E) of non activated palygorskite was equal to 17.14kJ.mol-1, former factors of Arrhenius was equal to 4.19×10-5 m2.s-1.

'Up-Hill' Interdiffusion and Accompanying Effects in Ternary Cu-Ni-5 at. % Sn(In) Systems

2005 ◽  
Vol 237-240 ◽  
pp. 456-461 ◽  
Author(s):  
Semen Kornienko ◽  
Lyudmila N. Paritskaya ◽  
V.V. Bogdanov
Keyword(s):  
Activation Energy ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Kinetic Equations ◽  
Diffusion Activation Energy ◽  
Phase Growth ◽  
Exponential Factor ◽  
Temperature Range ◽  
Kinetics Of ◽  
Diffusion Activation

Kinetics of phase growth in multiphase Cu-Sn and Ni-Sn systems and effect of third substitutive component (Ni or Cu respectively) were studied experimentally in temperature range 160-220oC and analyzed theoretically. Kinetic equations for calculation of diffusion coefficients in growing competitive phases were obtained. It was found that the substitutive components accelerated phase growth lowering the values of diffusion activation energy and pre-exponential factor. As a result the growth rates of competitive phases Cu6Sn5 and Cu3Sn in Cu-Sn system changed with substitutive Ni so, that only one (CuNi)6Sn5 phase survived whereas (CuNi)3Sn phase was suppressed. Obtained results are discussed in terms of higher disordering caused by substitutive components in ternary phases as compared with binary ones.

scholarly journals Thermally stimulated oxygen desorption in Sr2FeMoO6-δ

2018 ◽  
Vol 4 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Nikolay A. Kalanda
Keyword(s):  
Activation Energy ◽  
Oxygen Diffusion ◽  
Gas Flow ◽  
Oxygen Vacancies ◽  
Early Stage ◽  
Diffusion Activation Energy ◽  
Energy Calculation ◽  
Heating Rates ◽  
Oxygen Desorption ◽  
Diffusion Activation

Polycrystalline Sr2FeMoO6-δ specimens have been obtained by solid state synthesis from partially reduced SrFeO2,52 and SrMoO4 precursors. It has been shown that during oxygen desorption from the Sr2FeMoO6-δ compound in polythermal mode in a 5%H2/Ar gas flow at different heating rates, the oxygen index 6-δ depends on the heating rate and does not achieve saturation at T = 1420 K. Oxygen diffusion activation energy calculation using the Merzhanov method has shown that at an early stage of oxygen desorption from the Sr2FeMoO6-δ compound the oxygen diffusion activation energy is the lowest Еа = 76.7 kJ/mole at δ = 0.005. With an increase in the concentration of oxygen vacancies, the oxygen diffusion activation energy grows to Еа = 156.3 kJ/mole at δ = 0.06. It has been found that the dδ/dt = f (Т) and dδ/dt = f (δ) functions have a typical break which allows one to divide oxygen desorption in two process stages. It is hypothesized that an increase in the concentration of oxygen vacancies Vo•• leads to their mutual interaction followed by ordering in the Fe/Mo-01 crystallographic planes with the formation of various types of associations.

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