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Eric J. Mittemeijer - One of the best experts on this subject based on the ideXlab platform.
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a new method for the determination of the diffusion induced concentration profile and the Interdiffusion coefficient for thin film systems by auger electron spectroscopical sputter depth profiling
Journal of Materials Research, 2004Co-Authors: Jiang Y Wang, Eric J. MittemeijerAbstract:A new Auger electron spectroscopical sputter depth profiling method was developed to determine the Interdiffusion coefficient for the initial stage of diffusion annealing of thin films. The method is based on (i) adoption of an Interdiffusion model appropriate for the specimen investigated and (ii) convolution of an accordingly calculated diffusion-induced concentration profile with the smearing effects due to atomic mixing, surface/interface roughness, escape depth of the Auger electrons, and preferential sputtering. The diffusion-induced concentration profile and the Interdiffusion coefficient are determined by fitting in an iterative least-squares procedure of the calculated Auger electron spectroscopical depth profile to the measured one. The method was applied to bilayered and multilayered structures, exhibiting dominant grain-boundary diffusion and dominant volume diffusion, respectively. A very small extent of Interdiffusion, characterized by diffusion distances as small as 1 nm, could be quantified.
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determination of the Interdiffusion coefficient for si al multilayers by auger electron spectroscopical sputter depth profiling
Thin Solid Films, 2003Co-Authors: Jiang Y Wang, Eric J. Mittemeijer, A Zalar, Yonghao ZhaoAbstract:Initial stage Interdiffusion processes in Si/Al multilayer structures were studied quantitatively by means of Auger electron spectroscopical sputter depth profiling. The Al sublayers and the Si sublayers were sputter deposited onto a Si(111) substrate. The initial stage of the Interdiffusion at the location of the Si/Al interfaces was induced by heating the specimens isothermally in an argon atmosphere at 150, 165 and 180 °C for 20 min, and at 165 °C, additionally, for 10 and 30 min. It was found that, in such sputtering prepared multilayer structures, Interdiffusion across interfaces near the surface of the multilayer is faster than across interfaces in the deeper part of the layer. Measured depth profiles of the annealed specimens were compared with that of the as-deposited specimen after quantitative evaluation according to the so-called MRI (mixing-roughness-information depth)-model. As a result, values of the Interdiffusion coefficient as a function of the depth beneath the surface were obtained.
Yongho Sohn - One of the best experts on this subject based on the ideXlab platform.
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Interdiffusion and impurity diffusion in polycrystalline mg solid solution with al or zn
Journal of Alloys and Compounds, 2014Co-Authors: Catherine Kammerer, Nagraj S Kulkarni, R J Warmack, Yongho SohnAbstract:Abstract Interdiffusion and impurity diffusion in Mg binary solid solutions, Mg(Al) and Mg(Zn) were investigated at temperatures ranging from 623 to 723 K. Interdiffusion coefficients were determined via the Boltzmann–Matano Method using solid-to-solid diffusion couples assembled with polycrystalline Mg and Mg(Al) or Mg(Zn) solid solutions. In addition, the Hall method was employed to extrapolate the impurity diffusion coefficients of Al and Zn in pure polycrystalline Mg. For all diffusion couples, electron microprobe analysis was utilized for the measurement of concentration profiles. The Interdiffusion coefficient in Mg(Zn) was higher than that of Mg(Al) by an order of magnitude. Additionally, the Interdiffusion coefficient increased significantly as a function of Al content in Mg(Al) solid solution, but very little with Zn content in Mg(Zn) solid solution. The activation energy and pre-exponential factor for the average effective Interdiffusion coefficient in Mg(Al) solid solution were determined to be 186.8 (±0.9) kJ/mol and 7.69 × 10−1 (±1.80 × 10−1) m2/s, respectively, while those determined for Mg(Zn) solid solution were 139.5 (±4.0) kJ/mol and 1.48 × 10−3 (±1.13 × 10−3) m2/s. In Mg, the Zn impurity diffusion coefficient was an order of magnitude higher than the Al impurity diffusion coefficient. The activation energy and pre-exponential factor for diffusion of Al impurity in Mg were determined to be 139.3 (±14.8) kJ/mol and 6.25 × 10−5 (±5.37 × 10−4) m2/s, respectively, while those for diffusion of Zn impurity in Mg were determined to be 118.6 (±6.3) kJ/mol and 2.90 × 10−5 (±4.41 × 10−5) m2/s.
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simultaneous tracer diffusion and Interdiffusion in a sandwich type configuration to provide the composition dependence of the tracer diffusion coefficients
Philosophical Magazine, 2014Co-Authors: Irina V Belova, Yongho Sohn, Nagraj S Kulkarni, G E MurchAbstract:In this paper, a new formalism of a combined tracer and Interdiffusion experiment for a binary Interdiffusion couple is developed. The analysis requires an Interdiffusion couple that initially contains a thin layer of tracers of one or both of the constituent elements at the original interface of the couple (sandwich Interdiffusion experiment). This type of Interdiffusion experiment was first performed in 1958 by J.R. Manning. The theoretical analysis presented in this paper is based on a newly developed phenomenological theory of isotopic Interdiffusion combined with the Boltzmann–Matano formalism. This new analysis now provides the means to obtain the composition dependent Interdiffusion coefficient and tracer diffusion coefficients simultaneously from analysis of the Interdiffusion and tracer profiles in a single sandwich Interdiffusion experiment. The new analysis is successfully applied to the results of Manning’s original ‘sandwich Interdiffusion’ experiment in the Ag–Cd system (six couples in total...
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investigation of Interdiffusion behavior in the mo zr binary system via diffusion couple studies
International Journal of Refractory Metals & Hard Materials, 2014Co-Authors: A Paz E Y Puente, Dennis D Keiser, J Dickson, Yongho SohnAbstract:Abstract Zirconium has recently garnered attention for use as a diffusion barrier between U–Mo metallic nuclear fuels and Al alloy cladding. In order to gain a fundamental understanding of the diffusional interactions, the Interdiffusion behavior in the binary Mo–Zr system was investigated via solid-to-solid diffusion couples annealed in the temperature range of 750 to 1050 °C. A combination of scanning electron microscopy, X-ray energy dispersive spectroscopy, and electron probe microanalysis were used to examine the microstructure and concentration profiles across the Interdiffusion zone. A large β-Zr (cI2) solid solution layer and a thin (~ 1–2 μm) layer of Mo2Zr (cF24) developed in all couples. Parabolic growth constants and concentration dependent Interdiffusion coefficients were calculated for the Mo2Zr and Zr solid solution phases, respectively. The pre-exponential factor and activation energy for growth of the Mo2Zr phase were determined to be approximately 6.5 × 10− 15 m2/s and 90 kJ/mol, respectively. The Interdiffusion coefficient in β-Zr solid solution decreased with an increase in Mo concentration. Both the pre-exponential factors (2 × 10− 8 m2/s at 2 at.% Mo to near 5 × 10− 8 m2/s at 9 at.% Mo) and activation energies (140 kJ/mol at 2 at.% Mo to approximately 155 kJ/mol at 9 at.% Mo) of Interdiffusion coefficients were determined to increase with an increase in Mo concentration.
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simultaneous measurement of tracer and Interdiffusion coefficients an isotopic phenomenological diffusion formalism for the binary alloy
Philosophical Magazine, 2013Co-Authors: Irina V Belova, Yongho Sohn, Nagraj S Kulkarni, G E MurchAbstract:In this paper, a new development of the classic Onsager phenomenological formalism is derived using relations based on linear response theory. The development concerns the correct description of the fluxes of the atomic isotopes. The resulting expressions in the laboratory frame are surprisingly simple and consist of terms coming from the standard Interdiffusion expressions and from Fick’s first law, where the tracer diffusion coefficient is involved thus providing a better understanding of the relationship between the two approaches – Fick’s first law and the Onsager phenomenological formalism. From an experimental application perspective, the new development is applied to the binary alloy case. The formalism provides the means to obtain the Interdiffusion coefficient and tracer diffusion coefficients simultaneously from analysis of the Interdiffusion composition profiles in a single experiment.
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a double serpentine diffusion path for a ternary diffusion couple
Acta Materialia, 2000Co-Authors: Yongho Sohn, M A DayanandaAbstract:A double-serpentine diffusion path that crosses the straight line joining the terminal alloy compositions twice on a ternary isotherm is reported for a diffusion couple assembled with two {beta} (B{sub 2}) Fe-Ni-Al alloys and annealed at 1,000 C for 2 days. The couple developed a Ni concentration profile that exhibited two regions of mass loss separated by a region of mass gain on one side of the Matano plant. With an additional couple whose path intersected the double serpentine path, ternary Interdiffusion coefficients were determined at the composition of intersection. Also, average values of the ternary Interdiffusion coefficients, D{sub ij}{sup Fe} (i,j = Al, Ni), were determined over selected composition ranges of the couple and employed to model the concentration profiles. The cross D{sub NiAl}{sup Fe} coefficient was negative and comparable in magnitude to the main D{sub NiNi}{sup Fe} coefficient. The double-serpentine diffusion path was characterized by large diffusional interactions among the components and appreciable variations in the Interdiffusion coefficients over different compositional ranges.
G E Murch - One of the best experts on this subject based on the ideXlab platform.
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comments on experimental assessment of the thermodynamic factor for diffusion in cocrfeni and cocrfemnni high entropy alloys
Scripta Materialia, 2019Co-Authors: Irina V Belova, G E MurchAbstract:Abstract In this contribution, as comments to the paper in Scripta Materialia, v.157, p.81, 2018, we show that the pseudo-binary approach for analysis of Interdiffusion in multicomponent alloys has its reference value of the Manning factor (vacancy-wind factor) that is very different from true binary Interdiffusion. In true binary Interdiffusion, this factor is usually compared with unity. In the pseudo-binary analysis this reference value must be changed to the inverse of N1 + N2, where Ni are the compositions (mole fractions), and components 1 and 2 are the atomic components that have different terminal compositions in the corresponding experiment.
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comments on experimental assessment of the thermodynamic factor for diffusion in cocrfeni and cocrfemnni high entropy alloys
Social Science Research Network, 2019Co-Authors: Irina V Belova, G E MurchAbstract:In this contribution, as a response to the paper in Scripta Materialia, v.157, p.81, 2018, we show that the pseudo-binary approach for analysis of Interdiffusion in multicomponent alloys has its reference value of the Manning factor (vacancy-wind factor) that is very different from true binary Interdiffusion. In true binary Interdiffusion, this factor is usually compared with unity. In the pseudo-binary analysis this reference value must be changed to the inverse of N1+N2, where Ni are the compositions (mole fractions), and components 1 and 2 are the atomic components that have different terminal compositions in the corresponding experiment.
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combined Interdiffusion and self diffusion analysis in al cu liquid diffusion couple
Scripta Materialia, 2018Co-Authors: Irina V Belova, G E Murch, Elke Sondermann, David Heuskin, Florian Kargl, Benjamin Ignatzi, Andreas MeyerAbstract:Abstract In this paper, a recent combined isotope and Interdiffusion analysis is adapted to the case of binary liquid alloys. Shear-cell Interdiffusion experiments with a layer enriched in 65 Cu sandwiched between the Interdiffusion couple ends have been performed on liquid Al-Cu that is suitable for demonstration of the application of this analysis. (Note that the analysis is not limited to the use of the shear-cell technique.) The self-diffusion coefficient of Cu is then obtainable as a function of composition. Results of the new analysis are in good agreement with an independently measured Cu self (tracer) diffusion coefficient at two compositions.
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finite difference solution of the diffusion equation and calculation of the Interdiffusion coefficient using the sauer freise and hall methods in binary systems
Procedia Engineering, 2015Co-Authors: Tanvir Ahmed, Irina V Belova, G E MurchAbstract:The study of concentration dependent diffusion is important in the field of alloys and semiconductors. It is a key issue to calculate accurate Interdiffusion coefficients using experimentally obtained concentration profiles. The Boltzmann-Matano (BM) method is often used for determining diffusion coefficients. But this technique has some shortcomings in calculating an accurate Interdiffusion coefficient. Because of this, the Sauer and Freise (SF) method (which is a clever modification of the BM method) is more useful fo r calculating the Interdiffusion coefficient. The Hall Method (HM) was specifically designed for determining the Interdiffusion coefficient at the low and high concentration limits. In the present study, concentration profiles have been numerically generated as a solution to the Interdiffusion problem in a binary system when the Interdiffusion coefficient is dependent on concentration. This has been done using an explicit finite difference method. A comparative study of the HM, BM and SF methods has been performed using the generated concentration profiles. This allows for a direct comparison between the SF, BM and HM techniques. Present results clearly indicate that the HM technique can only be applicable when the Interdiffusion coefficient is constant (independent of concentration) or almost constant at the low concentration regions. In all other cases the SF method gives the best agreement with the input Interdiffusion function. © 2015 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of organizing committee of the 6th BSME International Conference on Thermal Engineering (ICTE 2014).
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simultaneous tracer diffusion and Interdiffusion in a sandwich type configuration to provide the composition dependence of the tracer diffusion coefficients
Philosophical Magazine, 2014Co-Authors: Irina V Belova, Yongho Sohn, Nagraj S Kulkarni, G E MurchAbstract:In this paper, a new formalism of a combined tracer and Interdiffusion experiment for a binary Interdiffusion couple is developed. The analysis requires an Interdiffusion couple that initially contains a thin layer of tracers of one or both of the constituent elements at the original interface of the couple (sandwich Interdiffusion experiment). This type of Interdiffusion experiment was first performed in 1958 by J.R. Manning. The theoretical analysis presented in this paper is based on a newly developed phenomenological theory of isotopic Interdiffusion combined with the Boltzmann–Matano formalism. This new analysis now provides the means to obtain the composition dependent Interdiffusion coefficient and tracer diffusion coefficients simultaneously from analysis of the Interdiffusion and tracer profiles in a single sandwich Interdiffusion experiment. The new analysis is successfully applied to the results of Manning’s original ‘sandwich Interdiffusion’ experiment in the Ag–Cd system (six couples in total...
Irina V Belova - One of the best experts on this subject based on the ideXlab platform.
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comments on experimental assessment of the thermodynamic factor for diffusion in cocrfeni and cocrfemnni high entropy alloys
Scripta Materialia, 2019Co-Authors: Irina V Belova, G E MurchAbstract:Abstract In this contribution, as comments to the paper in Scripta Materialia, v.157, p.81, 2018, we show that the pseudo-binary approach for analysis of Interdiffusion in multicomponent alloys has its reference value of the Manning factor (vacancy-wind factor) that is very different from true binary Interdiffusion. In true binary Interdiffusion, this factor is usually compared with unity. In the pseudo-binary analysis this reference value must be changed to the inverse of N1 + N2, where Ni are the compositions (mole fractions), and components 1 and 2 are the atomic components that have different terminal compositions in the corresponding experiment.
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comments on experimental assessment of the thermodynamic factor for diffusion in cocrfeni and cocrfemnni high entropy alloys
Social Science Research Network, 2019Co-Authors: Irina V Belova, G E MurchAbstract:In this contribution, as a response to the paper in Scripta Materialia, v.157, p.81, 2018, we show that the pseudo-binary approach for analysis of Interdiffusion in multicomponent alloys has its reference value of the Manning factor (vacancy-wind factor) that is very different from true binary Interdiffusion. In true binary Interdiffusion, this factor is usually compared with unity. In the pseudo-binary analysis this reference value must be changed to the inverse of N1+N2, where Ni are the compositions (mole fractions), and components 1 and 2 are the atomic components that have different terminal compositions in the corresponding experiment.
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combined Interdiffusion and self diffusion analysis in al cu liquid diffusion couple
Scripta Materialia, 2018Co-Authors: Irina V Belova, G E Murch, Elke Sondermann, David Heuskin, Florian Kargl, Benjamin Ignatzi, Andreas MeyerAbstract:Abstract In this paper, a recent combined isotope and Interdiffusion analysis is adapted to the case of binary liquid alloys. Shear-cell Interdiffusion experiments with a layer enriched in 65 Cu sandwiched between the Interdiffusion couple ends have been performed on liquid Al-Cu that is suitable for demonstration of the application of this analysis. (Note that the analysis is not limited to the use of the shear-cell technique.) The self-diffusion coefficient of Cu is then obtainable as a function of composition. Results of the new analysis are in good agreement with an independently measured Cu self (tracer) diffusion coefficient at two compositions.
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finite difference solution of the diffusion equation and calculation of the Interdiffusion coefficient using the sauer freise and hall methods in binary systems
Procedia Engineering, 2015Co-Authors: Tanvir Ahmed, Irina V Belova, G E MurchAbstract:The study of concentration dependent diffusion is important in the field of alloys and semiconductors. It is a key issue to calculate accurate Interdiffusion coefficients using experimentally obtained concentration profiles. The Boltzmann-Matano (BM) method is often used for determining diffusion coefficients. But this technique has some shortcomings in calculating an accurate Interdiffusion coefficient. Because of this, the Sauer and Freise (SF) method (which is a clever modification of the BM method) is more useful fo r calculating the Interdiffusion coefficient. The Hall Method (HM) was specifically designed for determining the Interdiffusion coefficient at the low and high concentration limits. In the present study, concentration profiles have been numerically generated as a solution to the Interdiffusion problem in a binary system when the Interdiffusion coefficient is dependent on concentration. This has been done using an explicit finite difference method. A comparative study of the HM, BM and SF methods has been performed using the generated concentration profiles. This allows for a direct comparison between the SF, BM and HM techniques. Present results clearly indicate that the HM technique can only be applicable when the Interdiffusion coefficient is constant (independent of concentration) or almost constant at the low concentration regions. In all other cases the SF method gives the best agreement with the input Interdiffusion function. © 2015 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of organizing committee of the 6th BSME International Conference on Thermal Engineering (ICTE 2014).
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simultaneous tracer diffusion and Interdiffusion in a sandwich type configuration to provide the composition dependence of the tracer diffusion coefficients
Philosophical Magazine, 2014Co-Authors: Irina V Belova, Yongho Sohn, Nagraj S Kulkarni, G E MurchAbstract:In this paper, a new formalism of a combined tracer and Interdiffusion experiment for a binary Interdiffusion couple is developed. The analysis requires an Interdiffusion couple that initially contains a thin layer of tracers of one or both of the constituent elements at the original interface of the couple (sandwich Interdiffusion experiment). This type of Interdiffusion experiment was first performed in 1958 by J.R. Manning. The theoretical analysis presented in this paper is based on a newly developed phenomenological theory of isotopic Interdiffusion combined with the Boltzmann–Matano formalism. This new analysis now provides the means to obtain the composition dependent Interdiffusion coefficient and tracer diffusion coefficients simultaneously from analysis of the Interdiffusion and tracer profiles in a single sandwich Interdiffusion experiment. The new analysis is successfully applied to the results of Manning’s original ‘sandwich Interdiffusion’ experiment in the Ag–Cd system (six couples in total...
Jiang Y Wang - One of the best experts on this subject based on the ideXlab platform.
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determination of Interdiffusion coefficient in nanolayered structures by auger electron spectroscopical sputter depth profiling
Advanced Materials Research, 2011Co-Authors: Jiang Y WangAbstract:A general method was developed for determination of Interdiffusion coefficient in nanolayered structures by Auger electron spectroscopical (AES) sputter depth profiling. The procedures of this method are as follows: (1) the concentration depth profile of annealed sample is calculated from its as-grown layered structure by adopting a suitable diffusion model; (2) this diffusion concentration depth profile is convoluted with a resolution function provided by the mixing-roughness-information depth (MRI)-model and as a result a calculated AES depth profile is obtained; (3) the Interdiffusion coefficient is determined by fitting the calculated AES depth profile to the measured one. As an example, the Interdiffusion coefficient parameters, the pre-exponential factor and the activation energy, were determined as 4.7×10-18 m2/s and 0.76 eV, respectively, for a GexSi1-x/Si multilayered nanostructure with Ge-Si alloyed layers of 2.2, 4.3 and 2.2 nm thickness in Si matrix.
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a new method for the determination of the diffusion induced concentration profile and the Interdiffusion coefficient for thin film systems by auger electron spectroscopical sputter depth profiling
Journal of Materials Research, 2004Co-Authors: Jiang Y Wang, Eric J. MittemeijerAbstract:A new Auger electron spectroscopical sputter depth profiling method was developed to determine the Interdiffusion coefficient for the initial stage of diffusion annealing of thin films. The method is based on (i) adoption of an Interdiffusion model appropriate for the specimen investigated and (ii) convolution of an accordingly calculated diffusion-induced concentration profile with the smearing effects due to atomic mixing, surface/interface roughness, escape depth of the Auger electrons, and preferential sputtering. The diffusion-induced concentration profile and the Interdiffusion coefficient are determined by fitting in an iterative least-squares procedure of the calculated Auger electron spectroscopical depth profile to the measured one. The method was applied to bilayered and multilayered structures, exhibiting dominant grain-boundary diffusion and dominant volume diffusion, respectively. A very small extent of Interdiffusion, characterized by diffusion distances as small as 1 nm, could be quantified.
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determination of the Interdiffusion coefficient for si al multilayers by auger electron spectroscopical sputter depth profiling
Thin Solid Films, 2003Co-Authors: Jiang Y Wang, Eric J. Mittemeijer, A Zalar, Yonghao ZhaoAbstract:Initial stage Interdiffusion processes in Si/Al multilayer structures were studied quantitatively by means of Auger electron spectroscopical sputter depth profiling. The Al sublayers and the Si sublayers were sputter deposited onto a Si(111) substrate. The initial stage of the Interdiffusion at the location of the Si/Al interfaces was induced by heating the specimens isothermally in an argon atmosphere at 150, 165 and 180 °C for 20 min, and at 165 °C, additionally, for 10 and 30 min. It was found that, in such sputtering prepared multilayer structures, Interdiffusion across interfaces near the surface of the multilayer is faster than across interfaces in the deeper part of the layer. Measured depth profiles of the annealed specimens were compared with that of the as-deposited specimen after quantitative evaluation according to the so-called MRI (mixing-roughness-information depth)-model. As a result, values of the Interdiffusion coefficient as a function of the depth beneath the surface were obtained.
