Pressure effects on the diffusion of boron and phosphorus in silicon

2019 ◽  
Vol 33 (23) ◽  
pp. 1950267
Author(s):  
Phan Thi Thanh Hong ◽  
Vu Van Hung ◽  
Nguyen Van Nghia ◽  
Ho Khac Hieu
Keyword(s):  
Diffusion Coefficients ◽  
Activation Volume ◽  
Ambient Pressure ◽  
Diffusion Mechanism ◽  
Potential Method ◽  
Activation Energies ◽  
Pressure Effects ◽  
Arrhenius Behavior ◽  
Work Pressure ◽  
Phosphorus In Silicon

In this work, pressure effects on the diffusion of boron and phosphorus in silicon have been investigated by using the statistical moment method. We consider the diffusion of boron and phosphorus in silicon for wide temperature and pressure ranges revealing the Arrhenius behavior of diffusion coefficients. Activation energies of diffusion of boron and phosphorus in silicon are derived, respectively, as 3.41 and 3.20 eV at ambient pressure. Our work shows that when pressure increases, the diffusivity of B is enhanced characterized by an activation volume of [Formula: see text] ([Formula: see text] is the atomic volume) at temperature 1083 K; and the diffusivity of P is reduced indicated by an activation volume of [Formula: see text] at 1113 K. Our results of activation energies and diffusion coefficients are in agreement with recent experimental measurements and ab initio calculations. This work proposes a potential method to investigate the diffusion mechanism in silicon solar cell.

Diffusion of He, Ne, and Ar in Vitreous and Partially Devitrified Germani um Dioxide

1972 ◽  
Vol 27 (4) ◽  
pp. 617-623
Author(s):  
W.W. Brandt ◽  
B. Rauch ◽  
J. Wagner
Keyword(s):  
Diffusion Coefficients ◽  
Arrhenius Equation ◽  
Diffusion Mechanism ◽  
Preexponential Factor ◽  
Activation Energies ◽  
Transition Range ◽  
Critical Dimensions ◽  
Glass Transition Range ◽  
Diffusion Paths ◽  
Solubility Coefficients

Abstract The diffusion coefficients of He, Ne, and Ar in various samples of GeO2 and approximate values for the corresponding solubility coefficients were obtained from nonisothermal and isothermal desorption experiments. The data show trends similar to those obtained on fused SiO2 , and are interpreted by assuming that the glasses contain many interstices of different critical dimensions and a variety of diffusion paths corresponding to a range of activation energies. Some annealed and partially devitrified samples were studied and the activation energies of diffusion were found to be relatively high. In a few cases, the measurements were extended into and above the glass transition range (∼570°) ; the resulting activation energy and the preexponential factor of the Arrhenius equation for the diffusion coefficient were markedly increased, indicating that the diffusion mechanism is probably drastically changed.

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

Pressure Effects on the Interactions of the Sarcoplasmic Reticulum Calcium Transport Enzyme with Calcium and para-Nitrophenyl Phosphate

1987 ◽  
Vol 42 (5) ◽  
pp. 641-652 ◽  
Author(s):  
Wilhelm Hasselbach ◽  
Lore Stephan
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Transport ◽  
Activation Volume ◽  
Reaction Scheme ◽  
Pressure Effects ◽  
Calcium Dependent ◽  
Nitrophenyl Phosphate ◽  
Hydrolysis Of ◽  
Sarcoplasmic Reticulum Calcium ◽  
Effect Of Hydrostatic Pressure

The effect of hydrostatic pressure on calcium dependent p-nitrophenyl phosphate hydrolysis of the sarcoplasmic reticulum calcium transport enzyme has been investigated at different degree of enzyme saturation by calcium and Mg-p-nitrophenyl phosphate to distinguish between activation and binding volumes. The enzyme saturated by both ligands displays a significant dependence of the activation volume on pressure, rising from 20 ml/mol at atmospheric pressure (0.1 MPa) to 80 ml/mol at 100 MPa. At subsaturating concentration of Mg-p-nitrophenyl phosphate an activation volume of 35 ml/mol prevails between 0.1 and 40 MPa. At subsaturating concentration of calcium the activation volume approximates 80 ml/mol in the same pressure range. The binding volume for both substrates is likewise pressure dependent falling from 20 ml/mol to 0 ml/mol for Mg-p-nitrophenyl phosphate and rising from 67 ml/mol to 155 ml/mol for calcium. The pressure dependence of activation and binding volumes is analysed on account of a simplified reaction scheme yielding activation volumes and rate constants for individual reaction steps.

Thermooxidative Aging Studies on Silicone Rubber and Lifetime Prediction

2013 ◽  
Vol 777 ◽  
pp. 11-14
Author(s):  
You Shan Wang ◽  
Sha Sha Jiang ◽  
Yu Peng Liu
Keyword(s):  
Silicone Rubber ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Activation Energies ◽  
Lifetime Prediction ◽  
Arrhenius Behavior ◽  
Compression Set ◽  
Degradation Processes ◽  
Aging Studies ◽  
Significant Compression

Silicone rubber have been aged in air while under 25% compression at temperature up to 250°C. These studies examined the compression set of silicone rubber at accelerated (elevated) temperatures and were then used to make predictions about compression set at room temperature. The data obtained could be amenable to timetemperature superposition and Arrhenius treatment. The results suggest the presence of two degradation processes with activation energies of 71.6 kJ mol-1 (for temperatures above 165 °C) and 26.08 kJ mol-1 (for temperatures below 165 °C). Based on the extrapolation of the non-Arrhenius behavior, it was estimated that significant compression set loss would occur after around 67 years at 25 °C.

Graphitization of diamond at zero pressure and at a high pressure

1972 ◽  
Vol 328 (1574) ◽  
pp. 413-427 ◽  
Keyword(s):  
High Pressure ◽  
Activation Volume ◽  
Activation Energies ◽  
Single Atom ◽  
Diamond Surface ◽  
Temperature Range ◽  
Natural Diamonds ◽  
Rate Controlling Step

Natural diamonds have been heated in the temperature range of 1850 to 2000 °C at zero pressure and the rates at which diamond transforms to graphite measured. For {111} and {110} surfaces activation energies of 253+18 and 174+12 kcal mol -1 (1159 + 75 and 728 + 50 kJ/mol) respectively have been obtained. Diamonds have also been heated in the temperature range of 1950 to 2200 °C under a pressure of 48 + 3 kbar (4.8 + 0.3 GPa) and an activation volume of about 10 cm 3 mol -1 obtained for both {111} and {110} surfaces. It is proposed that the rate controlling process in the graphitization of diamond is the detachment of a single atom from the diamond surface. This is contrary to previous proposals in which the detachment of groups of atoms have been considered to be the rate-controlling process. In the present work, it is suggested that the rate-controlling step for graphitization is the detachment of a triply bonded atom from a {111} surface and of a doubly bonded atom from a {110} surface.

Dielectric Studies of 4-w-Hexyloxy-4’-Cyanobiphenyl (60CB) at Elevated Pressure

1999 ◽  
Vol 54 (6-7) ◽  
pp. 365-369 ◽  
Author(s):  
S. Urban ◽  
M. Smoluchowski
Keyword(s):  
Dielectric Permittivity ◽  
Order Parameter ◽  
Nematic Phase ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Ambient Pressure ◽  
Relaxation Times ◽  
Elevated Pressure ◽  
Dielectric Anisotropy ◽  
Dielectric Studies

Abstract The principal dielectric permittivity components in the nematic phase of 4-rc-hexyloxy-4’-cyanobiph-enyl (60CB) were measured as functions of temperature at ambient pressure and as functions of pres-sure up to 100 MPa at several constant temperatures. The dielectric anisotropy is analized in the frame of the Maier-Meier equations. The pressure dependence of the order parameter is deduced. Preliminary results for the activation volume and activation enthalpy from the pressure and temperature dependenc-es of the longitudinal relaxation times are obtained.

Diffusion and its Application in NiMnGa Alloys

2018 ◽  
Vol 19 ◽  
pp. 80-95 ◽  
Author(s):  
Le Zhou ◽  
Yong Ho Sohn
Keyword(s):  
Crystal Structure ◽  
Martensitic Transformation ◽  
Phase Diagrams ◽  
Diffusion Coefficients ◽  
Diffusion Couples ◽  
Arrhenius Behavior ◽  
Ferromagnetic Shape Memory Alloys ◽  
Two Phase ◽  
Austenitic Phase ◽  
Practical Applications

Heusler NiMnGa alloys are often categorized as ferromagnetic shape memory alloys or magnetocaloric materials, which are important for both practical applications and fundamental research. The NiMnGa alloys undergo a series of diffusion and diffusionless transformation from high temperature to low temperature. Among these transformation, martensitic transformation from austenitic phase to martensitic phase is critical in determining the properties of the alloys. Although martensitic transformation is considered diffusionless, diffusion also has important applications in the research of NiMnGa alloysDiffusion couples along with equilibrium alloys have been used to determine the ternary phase diagrams in NiMnGa alloys. Phase diagrams are important in selecting NiMnGa alloys, in particular two-phase NiMnGa alloys for practical applications. Furthermore, the diffusion couples effectively assist in the determination of compositions that exhibit martensitic transformation temperature near room temperature. Diffusion coefficients have been assessed for NiMnGa alloys. Tracer diffusivity of Ni, Mn and Ga was reported in a wide temperature range and followed Arrhenius behavior. Two different activation energies were obtained, corresponding to B2 and L21 crystal structure, respectively. Interdiffusion coefficients for NiMnGa alloys with B2 crystal structure are measured, which showed that Ni diffuses the fastest, followed by Mn then Ga. The diffusion coefficients provide useful information for fabricating NiMnGa alloys through diffusional process.A combinatorial approach involving diffusion couples and advance characterization has been developed to investigate the mechanical properties, microstructure and crystallography of NiMnGa alloys rapidly and systematically over a large compositional range. The composition-dependent modulus and hardness for NiMnGa alloys was extracted from the diffusion couples with the help of nanoindentation. Martensitic phases with non-modulated and various modulated crystal structures, and austenitic phase were identified in the interdiffusion zones by transmission electron microscopy. The results demonstrate the capability of using diffusion couples to speed up the discovery of new NiMnGa alloys or other similar alloys showing martensitic transformation.

Sedimentation of Substitutional Solute Atoms in Condensed Matter: New Type of Diffusion

2005 ◽  
Vol 237-240 ◽  
pp. 30-37 ◽  
Author(s):  
Tsutomu Mashimo
Keyword(s):  
Gravity Field ◽  
Diffusion Coefficients ◽  
Materials Science ◽  
Condensed Matter ◽  
Diffusion Mechanism ◽  
Science Research ◽  
Substitutional Solute ◽  
Self Consistent ◽  
New Type ◽  
Solute Atoms

Ultra-strong gravitational field (Mega-gravity field) causes the sedimentation of even atoms (diffusion), and is expected to create a nonequilibrium crystal-chemical state in multi-component condensed matter. However, the materials science research under mega-gravity field has now remained as an unexploited field, while the sedimentation of molecules or polymer had been used in biochemistory. We presented a self-consistent diffusion equation for sedimentation of atoms in condensed matter. Next, we developed an ultracentrifuge apparatus to generate strong acceleration field of over 1 million (1x106) g at temperature range up to 〜300 °C, and, recently, succeeded in realization of the sedimentation of substitutional solute atoms in some alloys of Bi-Sb, In-Pb, Bi-Pb systems, etc. The diffusion coefficients in sedimentation on Bi-Sb alloy were estimated to be much greater than those at normal conditions by a factor of >20. It is suggested that the sedimentation of substitutional atoms in solids or liquids can be explained in a new type of diffusion, where the diffusion mechanism for substitutional solute atoms was yet unknown. In this article, the recent progress in the investigation of sedimentation of atoms under mega-gravity field is reviewed, and the diffusion mechanism is discussed. The application of the mega-gravity field is also discussed.

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