Diffusion in Cu(Al) Solid Solution

2008 ◽  
Vol 279 ◽  
pp. 63-69 ◽  
Author(s):  
A. Laik ◽  
K. Bhanumurthy ◽  
G.B. Kale
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Temperature Dependence ◽  
Bulk Diffusion ◽  
Impurity Diffusion ◽  
Solid Solution Phase ◽  
Temperature Range ◽  
State Diffusion ◽  
Pure Cu ◽  
Interdiffusion Coefficients

The solid state diffusion characteristics in the Cu(Al) solid solution phase, was investigated in the temperature range of 1023–1223 K using single phase bulk diffusion couples between pure Cu/Cu- 10 at.% Al. The interdiffusion coefficients, D, were calculated using Boltzmann–Matano method and Hall’s method from the concentration profiles of the couples that were determined using EPMA. The interdiffusion coefficients (D) calculated ranges between 1.39 X 10−14 and 3.97 X 10−13 m2/s in the temperature range of 1023 to 1223 K. The composition and temperature dependence of D were established. The activation energy for interdiffusion varies from 123.1 to 134.2 kJ/mol in the concentration range 1 at. % ≤ CAl ≤ 9 at. %. The impurity diffusion coefficient of Al in Cu is determined by extrapolating the interdiffusion coeffficient values to infinite dilution of the alloy i.e CAl →0 and its temperature dependence was also established. The activation energy for impurity diffusion of Al in Cu was found to be 137.1 kJ/mol.

About Fe Diffusion in Cu

2012 ◽  
Vol 323-325 ◽  
pp. 171-176 ◽  
Author(s):  
D. Prokoshkina ◽  
A.O. Rodin ◽  
V. Esin
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Grain Boundary ◽  
Temperature Dependence ◽  
Boundary Diffusion ◽  
Bulk Diffusion ◽  
Grain Boundary Diffusion ◽  
Radiotracer Technique ◽  
Exponential Factor ◽  
Temperature Range

The temperature dependence of the bulk diffusion coefficient of Fe in Cu is determined by EDX in the temperature range from 923 to 1273 K, , m2/s. These results are different from that obtained earlier by radiotracer technique: activation energy is less by 30 kJ/mol and pre-exponential factor is 50 times smaller. Deviations from ideality of investigated solutions do not explain the differences; consequently, the thermodynamical factor would not responsible for such an effect. Fast grain boundary diffusion of Fe in Cu was not observed in the temperature range from 823 to 1073 K.

scholarly journals SYNTHESIS AND ELECTRICAL CONDUCTIVITY OF SOLID SOLUTIONS OF THE SYSTEM RbF-PbF2-SnF2

2019 ◽  
Vol 85 (5) ◽  
pp. 60-68
Author(s):  
Yuliay Pogorenko ◽  
Anatoliy Omel’chuk ◽  
Roman Pshenichny ◽  
Anton Nagornyi
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Solid Solutions ◽  
Basic Structure ◽  
Elementary Cell ◽  
Initial Structure ◽  
Fluoride Ions ◽  
Temperature Range ◽  
Order Of Magnitude

In the system RbF–PbF2–SnF2 are formed solid solutions of the heterovalent substitution RbxPb0,86‑xSn1,14F4-x (0 < x ≤ 0,2) with structure of β–PbSnF4. At x > 0,2 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded that do not correspond to the reflexes of the individual fluorides and can indicate the formation of a mixture of solid solutions of different composition. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Rb+ into the initial structure leads to an increase in the parameter a of the elementary cell from 5.967 for x = 0 to 5.970 for x = 0.20. The replacement of a part of leads ions to rubium ions an increase in electrical conductivity compared with β–PbSnF4 and Pb0.86Sn1.14F4. Insignificant substitution (up to 3.0 mol%) of ions Pb2+ at Rb+ at T<500 K per order of magnitude reduces the conductivity of the samples obtained, while the nature of its temperature dependence is similar to the temperature dependence of the conductivity of the sample β-PbSnF4. By replacing 5 mol. % of ions with Pb2+ on Rb+, the fluoride ion conductivity at T> 450 K is higher than the conductivity of the initial sample Pb0,86Sn1,14F4 and at temperatures below 450 K by an order of magnitude smaller. With further increase in the content of RbF the electrical conductivity of the samples increases throughout the temperature range, reaching the maximum values at x≥0.15 (σ573 = 0.34–0.41 S/cm, Ea = 0.16 eV and σ373 = (5.34–8.16)•10-2 S/cm, Ea = 0.48–0.51 eV, respectively). In the general case, the replacement of a part of the ions of Pb2+ with Rb+ to an increase in the electrical conductivity of the samples throughout the temperature range. The activation energy of conductivity with an increase in the content of RbF in the low-temperature region in the general case increases, and at temperatures above 400 K is inversely proportional decreasing. The nature of the dependence of the activation energy on the concentration of the heterovalent substituent and its value indicate that the conductivity of the samples obtained increases with an increase in the vacancies of fluoride ions in the structure of the solid solutions.

Interdiffusion in Nb-Mo, Nb-Ti and Nb-Zr Systems

2012 ◽  
Vol 323-325 ◽  
pp. 491-496 ◽  
Author(s):  
Soma Prasad ◽  
Aloke Paul
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Diffusion Couple ◽  
Impurity Diffusion ◽  
Impurity Diffusion Coefficient ◽  
Different Temperatures ◽  
Diffusion Couple Technique ◽  
Interdiffusion Coefficients

Diffusion couple technique is used to study interdiffusion in Nb-Mo, Nb-Ti and Nb-Zr systems. Interdiffusion coefficients at different temperatures and compositions are determined using the relation developed by Wagner. The change in activation energy for interdiffusion with composition is determined. Further, impurity diffusion coefficient of the species are determined and compared with the available data in literature.

Diffusion in Co-Ni System Studied by Multifoil Technique

2011 ◽  
Vol 312-315 ◽  
pp. 466-471 ◽  
Author(s):  
V.D. Divya ◽  
U. Ramamurty ◽  
Aloke Paul
Keyword(s):  
Activation Energy ◽  
Binary System ◽  
Diffusion Couple ◽  
Diffusion Coefficients ◽  
Impurity Diffusion ◽  
Intrinsic Diffusion ◽  
Exponential Factor ◽  
Temperature Range

Diffusion couple experiments were performed in the Co-Ni binary system for determining inter-, impurity- and intrinsic-diffusion coefficients in the temperature range of 1050 - 1250°C. The activation energy and pre-exponential factor estimated for interdiffusion do not vary significantly with composition. The activation energy calculated for impurity diffusion experiments shows is higher than . Intrinsic diffusion coefficients estimated from the multifoil experiment show that Ni is the fastest diffusing species in this system.

Interface Controlled Diffusional Creep of Cu + 2.8 at.% Co Solid Solution

2012 ◽  
Vol 322 ◽  
pp. 33-39 ◽  
Author(s):  
Sergei Zhevnenko ◽  
Eugene Gershman
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Surface Tension ◽  
High Temperature ◽  
Creep Behavior ◽  
Pure Copper ◽  
Diffusional Creep ◽  
High Temperature Creep ◽  
Temperature Range ◽  
Different Temperatures

High-temperature creep experiments were performed on a Cu-2.8 ат.% Co solid solution. Cylindrical foils of 18 micrometers thickness were used for this purpose. Creep tests were performed in a hydrogen atmosphere in the temperature range of about from 1233 K to 1343 K and at stresses lower than 0.25 MPa. For comparison, a foil of pure copper and Cu-20 at.% Ni solid solution were investigated on high temperature creep. Measurements on the Cu foil showed classical diffusional creep behavior. The activation energy of creep was defined and turned out to be equal 203 kJ/mol, which is close to the activation energy of bulk self-diffusion of copper. There was a significant increase in activation energy for the Cu-20 at.% Ni solid solution. Its activation energy was about 273 kJ/mol. The creep behavior of Cu-Co solid solution was more complicated. There were two stages of diffusional creep at different temperatures. The extremely large activation energy (about 480 kJ/mol) was determined at relatively low temperature and a small activation energy (about 105 kJ/mol) was found at high temperatures. The creep rate of Cu-Co solid solution was lower than that of pure copper at all temperatures. In addition, the free surface tension of Cu-2.8 ат.% Co was measured at different temperatures from 1242 K to 1352 K. The surface tension increases in this temperature range from 1.6 N/m to 1.75 N/m. There were no features on the temperature dependence of the surface tension.

CREEP ACTIVATION ENERGY OF FLOW PROCESS IN Sn0.2Bi1.8Te3 SINGLE CRYSTALS

2004 ◽  
Vol 11 (04n05) ◽  
pp. 443-446
Author(s):  
P. H. SONI ◽  
C. F. DESAI ◽  
S. R. BHAVSAR
Keyword(s):  
Activation Energy ◽  
Time Dependence ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Vickers Microhardness ◽  
Indentation Creep ◽  
Flow Process ◽  
Creep Activation Energy ◽  
Temperature Range ◽  
Different Temperatures

Temperature dependence of the Vickers microhardness of Sn 0.2 Bi 1.8 Te 3 single crystals has been studied. Loading time dependence of microhardness at different temperatures has been used for creep study in the temperature range 303 K–373 K. The activation energy for indentation creep of the crystals has been evaluated.

Interdiffusion between the L12 trialuminides Al66Ti25Mn9 and Al67Ti25Cr8

1992 ◽  
Vol 7 (5) ◽  
pp. 1043-1045 ◽  
Author(s):  
K.S. Kumar ◽  
J.D. Whittenberger
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficients ◽  
Diffusion Couples ◽  
Temperature Range ◽  
Interdiffusion Coefficients ◽  
Mn Concentration

Interdiffusion coefficients (D) were determined in the temperature range 1373 K–1073 K (0.85 Tm−0.65 Tm) from concentration-distance profiles that were generated from Al66Ti25Mn9/Al67Ti25Cr8 diffusion couples. As both of these materials are completely soluble in one another, the couples were treated as pseudobinaries (particularly because the Ti and Al levels were similar), and the Matano approach was used to calculate diffusion coefficients. The variation in D with composition was determined and a minimum was noted at intermediate temperatures and a relative Mn concentration of 0.5. A maximum in activation energy for interdiffusion was also noted at this concentration where Q ≍ 350 kJ/mol.

Temperature Dependence of Sensitized Photocurrents between 200 and 293 K

1978 ◽  
Vol 33 (7) ◽  
pp. 822-826 ◽  
Author(s):  
H. Killesreiter
Keyword(s):  
Activation Energy ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Intermediate State ◽  
Electrochemical Cell ◽  
Reaction Scheme ◽  
Metal Electrodes ◽  
Temperature Range

With an oxacarbocyanine dye monolayer on the surface of a p-chloranil single crystal and sandwiched between metal electrodes the temperature dependence of sensitized photocurrents has been measured with this “dry” electrochemical cell in the temperature range from 200-293 K. The activation energy of 0.26 ± 0.02 eV is discussed in terms of a reaction scheme that involves a thermalization distance within the coulomb well of an intermediate state.

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