Chromium Diffusion in Sapphire Crystals: Influence of Preannealing Conditions

1998 ◽  
Vol 527 ◽  
Author(s):  
E. G. Gontier-Moya ◽  
F. Moya ◽  
J. Bigarre ◽  
D. Juve ◽  
D. Treheux ◽  
...  
Keyword(s):  
Reference Material ◽  
Single Crystals ◽  
Point Defects ◽  
Diffusion Coefficients ◽  
Bulk Diffusion ◽  
Annealing Treatment ◽  
Chromium Diffusion ◽  
Linear Defects ◽  
Surface Polishing ◽  
Order Of Magnitude

ABSTRACTChromium diffusion coefficients in alumina single crystals were evaluated from penetration profiles determined by the SIMS technique. The samples were previously annealed at 1000°C (1 hour), 1500°C (4 hours), and 1700°C (24 hours). Diffusion experiments were carried out at 1400°C during 10 hours.The results show that bulk diffusion coefficients are strongly dependent on preannealing conditions (temperature and time): they decrease by more than an order of magnitude when the preannealing temperature is increased from 1000°C to 1700°C.These results are discussed taking into account the dislocations and point defects in alumina. We consider the role played by the linear defects resulting from surface polishing, as well as point defects associated with impurities. It is found that the lowest defect concentration is achieved after an annealing treatment at 1700°C during 24 hours. The conditions for obtaining a, «reference material» are proposed.

Bulk Diffusion of Homovalent Non-Magnetic Atomic Probes of Titanium and Zirconium in Tungsten Single Crystals

2011 ◽  
Vol 319-320 ◽  
pp. 1-11 ◽  
Author(s):  
S.M. Klotsman ◽  
G.N. Tatarinova ◽  
Alexander N. Timofeev
Keyword(s):  
Single Crystals ◽  
Point Defects ◽  
Diffusion Coefficients ◽  
Periodic Table ◽  
Secondary Ion Mass Spectrometry ◽  
Volume Diffusion ◽  
Bulk Diffusion ◽  
The Self ◽  
Self Diffusion ◽  
Secondary Ion

The bulk diffusion of homovalent non-magnetic atomic probes (APs) from the IVB group of the periodic table of elements (PTE) – Ti and Zr in tungsten single crystals was investigated by sec-tioning, using secondary ion mass spectrometry (SIMS). The Arrhenius dependences had the fol-lowing parameters: DWTi - (D0)WTi = (3.00.4 ) x 10-4 m2s-1, enthalpy QWTi = (576 ± 9) kJ/mole; DWZr - (D0)WZr = (2.3  0.6) x 10-4 m2s-1, QWZr = (561 9) kJ/mole. The measured parameters (D0,Q)WTi,Zr of diffusion of Ti and Zr atomic probes (APs) in W are in accord with the empirical correlation: the diffusion coefficients of the substitutional APs coincide with the self-diffusion coefficients in W at (Tm)W – its melting temperature. Enthalpies QWTi,Zr,Hf of the volume diffusion of homovalent non-magnetic APs of the IVB group of periodic table of elements (PTE) - Ti, Zr and Hf increase with the decrease of relaxation volumes of the complexes «vacancy-IVBAP» in W lattice. The energies (E)WvacIVBAP of elastic relaxation of the complexes «vacancy-IVBAP» in W lattice were estimated. Electron contributions EDN to the energies EWvacIVBAP of interaction of the point defects in complexes «vacancy-IVBAP» increase relative to value EWvacIIIBAP of interac-tion of the point defects in complexes «vacancy-IIIBAP» with the growth of d-electrons number in comparison with the complexes «vacancy-IIIBAP».

Self-diffusion in gold single crystals at low temperatures

1968 ◽  
Vol 46 (23) ◽  
pp. 2589-2594 ◽  
Author(s):  
J. L. Whitton ◽  
G. V. Kidson
Keyword(s):  
Single Crystals ◽  
Diffusion Coefficients ◽  
Low Temperatures ◽  
Bulk Diffusion ◽  
Lattice Diffusion ◽  
Fast Diffusion ◽  
Initial Portion ◽  
Self Diffusion ◽  
Normal Lattice ◽  
Structure Sensitive

Self-diffusion in gold single crystals has been studied at temperatures between 335 to 390 °C for times between 15 and 30 min. The concentration profiles, obtained by use of a sensitive sectioning technique, consist of a region that appears to be characteristic of bulk diffusion, followed by a deeply penetrating 'tail' that is structure sensitive. Diffusion coefficients extracted from the initial portion of the curves are somewhat larger than those predicted from an extrapolation of high temperature measurements. The results are interpreted in terms of a combination of normal lattice diffusion and fast diffusion along dislocations.

Rutherford Backscattering Spectrometry Studies on Copper and Chromium Diffusion in Polyimide

1989 ◽  
Vol 153 ◽  
Author(s):  
Kyung W. Paik ◽  
Arthur L. Ruoff
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Annealing Treatment ◽  
Rutherford Backscattering ◽  
Fickian Diffusion ◽  
Chromium Diffusion ◽  
Diffusion Behavior ◽  
Slight Amount

AbstractDiffusion of Cu in polyimide(PI) film was observed after Cu evaporation on PI at room temperature. Annealing treatment significantly enhanced the diffusion of Cu. The diffusion coefficient measured at 200 and 400 C using the Fickian erfc solution are 3 × 10−14 and 1 × 10−13 cm2/sec, respectively. Cu shows the Fickian diffusion behavior. In contrast to Cu, no clearly measurable diffusion had occurred for an as-deposited Cr specimen and a specimen annealed at 400 C for 1 hour. However, for longer annealing times a slight amount of Cr diffused into PI because of the growth of the intermixed region. The diffusion coefficients of Cr at 200 and 400 C for less than 20 hours are 2 × 10−15 and 7 × 10−15 cm2/sec, respectively. The diffusion of Cr in PI shows non-Fickian behavior.

Rutherford Backscattering Spectrometry Studies on Copper and Chromium Diffusion in Polyimide

1989 ◽  
Vol 154 ◽  
Author(s):  
Kyung W. Paik ◽  
Arthur L. Ruoff
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Annealing Treatment ◽  
Rutherford Backscattering ◽  
Fickian Diffusion ◽  
Chromium Diffusion ◽  
Diffusion Behavior ◽  
Slight Amount

AbstractDiffusion of Cu in polyimide(PI) film was observed after Cu evaporation on PI at room temperature. Annealing treatment significantly enhanced the diffusion of Cu. The diffusion coefficient measured at 200 and 400 C using the Fickian erfc solution are 3 × 10−14 and 1 × 10−13 cm2/sec, respectively. Cu shows the Fickian diffusion behavior. In contrast to Cu, no clearly measurable diffusion had occurred for an as-deposited Cr specimen and a specimen annealed at 400 C for 1 hour. However, for longer annealing times a slight amount of Cr diffused into PI because of the growth of the intermixed region. The diffusion coefficients of Cr at 200 and 400 C for less than 20 hours are 2 × 10−15 and 7 × 10−15 cm2/sec, respectively. The diffusion of Cr in PI shows non-Fickian behavior.

Bulk Diffusion of Homovalent Atomic Probes of Vanadium and Niobium in Single Crystals of Tungsten

2012 ◽  
Vol 330 ◽  
pp. 1-10 ◽  
Author(s):  
S.M. Klotsman ◽  
G.N. Tatarinova ◽  
Alexander N. Timofeev
Keyword(s):  
Single Crystals ◽  
Diffusion Coefficients ◽  
Secondary Ion Mass Spectrometry ◽  
Volume Diffusion ◽  
Bulk Diffusion ◽  
Self Diffusion ◽  
Arrhenius Dependence ◽  
The Difference ◽  
Defect Interactions ◽  
Secondary Ion

The Volume Diffusion of Homovalent Atomic Probes (APs) from the VB Group of the Periodic Ta-Ble of Elements (PTE) – V and Nb in W Single Crystals Has Been Studied by Using the Method of Secondary Ion Mass Spectrometry (SIMS). the Parameters of the Arrhenius Dependence of the Coefficients DV of Vanadium Volume Diffusion in W Have Been Measured: (D0)V = (1.3  0.4) X 10-4 M2s-1 and QV = (564 ± 6) Kj/mol. the Parameters (D0,Q)Nb of the Bulk Diffusion of Nb Aps in W Have Been Estimated with the Help of Several Measured Coefficients Dnb and the Empirical Correlation [1,2]: (D = DWW)(Tm)W: the Diffusion Coefficients of Substitutional Non-Magnetic 5d-Aps Coincide with the Self-Diffusion Coefficients in W at its Melting Point (Tm)W. the Enthalpies Qnb,Ta of the Bulk Diffusion of Non-Magnetic (nm) Homovalent Aps from the VB Group of PTE – Nb and Ta [3] Also Coincide with the Relaxation Volumes vacVBAPs of Complexes “vacancies-VB Aps” in the W Lattice. Electron Contributions (EDN)vacVBAPs to the Energies Evacvbaps of Interaction of Point Defects in Complexes “vacancies- VB Nm- Aps” Are Lower than in Complexes “vacancies-IVB Nm- Aps” [4]. the Dependence of {EDN(n)}vacVBAPs the Electron Contributions (EDN)vacVBAPs on the Difference of N Numbers of Periods of PTE the Deviation of Contributions (EDN)vacVAPs for Vanadium Aps to En-Ergies Evacvaps of their Interaction in Complexes “vacancy-VAP” Has Been Determined. this Devi-Ation Is Conditioned by the Contribution of the Exchange Energy (Eexch)VAP of Vanadium to the En-Ergy Evacvaps of the Point-Defect Interactions in the Complex “vacancy-VAP”.

Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

Effect of Mn3+ doping on crystal structure, point defects, and optical properties in green Ca3(VO4)2 single crystals

2021 ◽  
pp. 111300
Author(s):  
Galina M. Kuz’micheva ◽  
Liudmila. I. Ivleva ◽  
Irina A. Kaurova ◽  
Evgeny V. Khramov ◽  
Victor B. Rybakov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Single Crystals ◽  
Point Defects

scholarly journals Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients

1974 ◽  
Vol 64 (6) ◽  
pp. 706-729 ◽  
Author(s):  
W. R. Redwood ◽  
E. Rall ◽  
W. Perl
Keyword(s):  
Cell Membrane ◽  
Membrane Permeability ◽  
Diffusion Coefficients ◽  
Bulk Diffusion ◽  
Red Cells ◽  
Cell Membrane Permeability ◽  
Red Cell ◽  
Cell Column ◽  
Red Cell Membrane ◽  
One Dimensional

The permeability coefficients of dog red cell membrane to tritiated water and to a series of[14C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell column was pulsed at one end with radiolabeled solute and diffusion was allowed to proceed for several hours. The distribution of radioactivity along the red cell column was measured by sequential slicing and counting, and the diffusion coefficient was determined by a simple plotting technique, assuming a one-dimensional diffusional model. In order to derive the red cell membrane permeability coefficient from the bulk diffusion coefficient, the red cells were assumed to be packed in a regular manner approximating closely spaced parallelopipeds. The local steady-state diffusional flux was idealized as a one-dimensional intracellular pathway in parallel with a one-dimensional extracellular pathway with solute exchange occurring within the series pathway and between the pathways. The diffusion coefficients in the intracellular and extracellular pathways were estimated from bulk diffusion measurements through concentrated hemoglobin solutions and plasma, respectively; while the volume of the extracellular pathway was determined using radiolabeled sucrose. The membrane permeability coefficients were in satisfactory agreement with the data of Sha'afi, R. I., C. M. Gary-Bobo, and A. K. Solomon (1971. J. Gen. Physiol. 58:238) obtained by a rapid-reaction technique. The method is simple and particularly well suited for rapidly permeating solutes.

Positron annihilation in fatigued copper

1982 ◽  
Vol 60 (2) ◽  
pp. 201-204 ◽  
Author(s):  
S. Kupca ◽  
D. P. Kerr ◽  
B. G. Hogg ◽  
Z. S. Basinski
Keyword(s):  
Single Crystals ◽  
Point Defects ◽  
High Purity ◽  
Low Temperatures ◽  
Annealing Process ◽  
Simple Diffusion ◽  
Diffusion Limited ◽  
Annealing Study ◽  
Positron Lifetimes ◽  
Trapping Process

Positron lifetimes have been measured in an isochronal annealing study of dynamically fatigued, high purity Cu single crystals. Decomposition of the lifetime spectra into two components results in a description of the annealing process in terms of the lifetime and fraction of trapped positrons. Positron lifetimes were also determined at a series of low temperatures (10–300 K) at different stages of annealing. The lifetime of positrons trapped at point defects is found to vary with temperature indicating that a description of the trapping process according to a simple diffusion limited model is not applicable.

Behaviour of Implanted Hydrogen in Gallium Phosphide Single Crystals

1988 ◽  
Vol 144 ◽  
Author(s):  
J. M. Zavada ◽  
R. G. Wilson ◽  
S. W. Novak ◽  
S. J. Pearton ◽  
A. R. Von Neida
Keyword(s):  
Mass Spectrometry ◽  
Single Crystals ◽  
Diffusion Coefficients ◽  
Gallium Phosphide ◽  
Secondary Ion Mass Spectrometry ◽  
Furnace Annealing ◽  
Higher Temperature ◽  
Redistribution Of Hydrogen ◽  
Secondary Ion ◽  
Post Implantation

ABSTRACTIn this paper we report on the depth distributions of implanted hydrogen in GaP crystals and the subsequent changes produced by post- implantation furnace annealing. A sulfur doped n+ GaP wafer has been implanted with 333 keV protons to a fluence of 5E15/cm+2. A similar wafer was implanted with 350 keV deuterons to the same fluence. Portions of each wafer have been furnace annealed at temperatures up to 500°C. The implanted hydrogen and the dopant S atoms were then depth profiled using secondary ion mass spectrometry (SIMS). The measurements show that the redistribution of hydrogen begins with annealing at about 300°C and proceeds both towards the surface and deeper into the substrate. The overall behavior is similar to that found previously for hydrogen in GaAs. However, in GaP crystals this redistribution begins at a higher temperature and proceeds more slowly in the implanted region. Based on the SIMS profiles, diffusion coefficients for hydrogen migrating into substrate are obtained.

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