Ion Beam Analysis of Diffusion in Polymer Melts

1984 ◽  
Vol 40 ◽  
Author(s):  
P. F. Green ◽  
P. J. Mills ◽  
C. J. Palmstrom ◽  
J. W. Mayer ◽  
E. J. Kramer
Keyword(s):  
Molecular Weight ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Depth Profiling ◽  
Kirkendall Effect ◽  
Tracer Diffusion ◽  
Polymer Chains ◽  
Self Diffusion ◽  
Beam Depth ◽  
Good Agreement

AbstractTwo ion beam depth profiling methods have been used to measure the diffusion of polymer chains of molecular weight M into a matrix of polymer of molecular weight P. In the first the displacement xm of Au markers at the original interface of a diffusion couple between polystyrene with P=2×107 and a thin film of PS with M<P is measured using Rutherford backscattering spectrometry. From this modern version of the Kirkendall effect we find x=0.4t8(D*t) 0 5, where D* the tracer diffusion coefficient of the M chains at 174°C, is found to be D*=O.007M−2cm2/sec, in good agreement with the D*=DR expected for the reptation mechanism. Forward recoil spectrometry, a technique in which the energies of recoiling deuterons are detected, is used to obtain concentration profiles, and hence D*, of deuterated PS M-chains diffusing into a hydrogenated PS P-chain matrix. When P>>M, D*=0.008M−2, in good agreement with the marker data. When P<P*(M) however D*; increases greatly as P decreases; P* increases slowly with increasing M. The results are predicted quantitatively by D*=DR+DCR, where DCR=0.10Me2/(Mp 3 ) describes the diffusion of the M-chain by release of its topological constraints (by diffusion of the surrounding P-chains) and Me is an entanglement molecular weight. D* for self-diffusion (M=P) is dominated by reptation except for M's close to Me.

scholarly journals Ion-beam depth-profiling studies of leached glasses

1982 ◽  
Vol 64 (1-4) ◽  
pp. 103-108 ◽  
Author(s):  
C. A. Houser ◽  
I. S. T. Tsong ◽  
W. B. White ◽  
A. L. Wintenberg ◽  
P. D. Miller ◽  
...  
Keyword(s):  
Ion Beam ◽  
Depth Profiling ◽  
Beam Depth

Diffusion in Polymer Alloy Melts

MRS Bulletin ◽  
1987 ◽  
Vol 12 (8) ◽  
pp. 42-47 ◽  
Author(s):  
Peter F. Green ◽  
Edward J. Kramer
Keyword(s):  
Diffusion Coefficient ◽  
Ion Beam ◽  
Excess Entropy ◽  
Tracer Diffusion ◽  
Polymer Chains ◽  
Mutual Diffusion ◽  
Entropy Of Mixing ◽  
Analysis Technique ◽  
The Matrix ◽  
The One

AbstractDiffusion in polymer alloys or blends can be used to extract information on the fundamentals of the dynamics of individual polymer chains in the melt and the thermodynamics of the interaction between unlike polymer species. The dynamics of individual chains are available from measurements of the tracer diffusion coefficients, D*, of the various species while the thermodynamics of interaction, represented by the Flory parameter, x, can be obtained from measurements of the mutual diffusion or interdiffusion coefficient, D. We will show that these quantities can be measured conveniently by forward recoil spectrometry (FRES), an ion beam analysis technique that can determine the concentration versus depth profile of polymers labeled with deuterium diffusing into unlabeled polymer matrices.For high enough molecular weight of the matrix, the tracer diffusion coefficient of both species in the blend scale as D0N−2, where N is the number of monomer segments per diffusing chain; the constant D0, however, can differ by more than 104 for chemically different molecules diffusing in the same blend, suggesting that conventional concepts of chain dynamics in melts, such as monomer friction coefficients, need to be reexamined. The mutual diffusion coefficient is controlled by the faster species in the blend (the one with the larger D*N product) in agreement with what was found in metallic alloys (but in sharp disagreement with the “slow” theory of mutual diffusion which predicts that the slower species controls). Since the combinatorial (ideal) entropy of mixing of polymers is low, the thermodynamic driving force for diffusion is dominated by enthalpy and excess entropy of mixing (x) to a degree unprecedented for atomic or small molecule systems. This means that one can observe not only a thermodynamic “slowing down” of diffusion when x becomes positive as one nears the spinodal but also a large thermodynamic “speeding up” of diffusion when x is negative. Measurements of mutual diffusion turn out to be one of the most sensitive methods available for measuring x.

Limits of Ion-Beam Depth-Profiling as Used in Diffusion Studies of Oxidation-Sensitive Materials

2002 ◽  
Vol 203-205 ◽  
pp. 147-152 ◽  
Author(s):  
H. Ehmler ◽  
A. Rehmet ◽  
Klaus Rätzke ◽  
Franz Faupel
Keyword(s):  
Ion Beam ◽  
Depth Profiling ◽  
Beam Depth ◽  
Diffusion Studies

Comparative Analysis of the Nucleation and Growth of Copper on Different Low-k Polymers

2001 ◽  
Vol 714 ◽  
Author(s):  
V. Zaporojtchenko ◽  
J. Erichsen ◽  
T. Strunskus ◽  
K. Behnke ◽  
F. Faupel ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Depth Profiling ◽  
Nucleation And Growth ◽  
Force Microscopy ◽  
Teflon Af ◽  
Atomic Force ◽  
Transmission Electron ◽  
Beam Depth ◽  
Low K

ABSTRACTIn this work we present investigations of the nucleation and growth of evaporated copper on several low-k polymers. The evolving interfaces were characterized using transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results were compared between the PMDA/ODA polyimide, Teflon AF 1601 and Silk®. A diffusion coefficient for copper atoms in Silk® determined by low energy ion-beam depth profiling in conjunction with XPS is reported.

Diffusion studies in polymer melts by ion beam depth profiling of hydrogen

Polymer ◽  
1986 ◽  
Vol 27 (7) ◽  
pp. 1063-1066 ◽  
Author(s):  
Peter F Green ◽  
Peter J Mills ◽  
Edward J Kramer
Keyword(s):  
Polymer Melts ◽  
Ion Beam ◽  
Depth Profiling ◽  
Beam Depth ◽  
Diffusion Studies

Polymer-Polymer Interdiffusion

1984 ◽  
Vol 40 ◽  
Author(s):  
Edward J. Kramer
Keyword(s):  
Molecular Weight ◽  
Diffusion Mechanism ◽  
Linear Chain ◽  
Tracer Diffusion ◽  
Polymer Chains ◽  
Polymer Interfaces ◽  
Topological Constraints ◽  
Constraint Release ◽  
Polymer Interdiffusion ◽  
Kinetics Of

AbstractInterdiffusion of polymer chains plays an important role in establishing good adhesion at polymer interfaces as well as in the kinetics of phase separation and mixing in polymer blends. Reptation, a process in which a given linear chain crawls along a primitive path defined by the topological constraints due to the surrounding chains, is thought to be the most important diffusion mechanism. A reptating chain of Volecular weight M should have a tracer diffusion coefficient given by D =DR =Do M−2, where D depends on the Rouse mobility of the chain and an entang ement molecular weight, Me. Because the topological constraints are assumed to be fixed, DR is independent of the molecular weight P of the polymer into which the M-chains are diffusing. In principle however if M is large enough and P is small enough the M-chain can diffuse by rearrangement of the P-chains surrounding it, a process called constraint release. The D for this process, DCR= αCRDoMe2/(MP3), where αCR is a constant approximately equal to 13, increases strongly with decreasing P. Recent experimental results, which give evidence for both reptation and constraint release, will be reviewed. These results have important implications for the diffusion of nonlinear polymer chains, e.g. stars and rings.

Element Profiles of Surface Layers Created by Metal Ion Beam Assisted Deposition

1993 ◽  
Vol 316 ◽  
Author(s):  
Sergei M. Duvanov ◽  
Alexander P. Kobzev ◽  
Alexander M. Tolopa
Keyword(s):  
Metal Ion ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Depth Profiling ◽  
Thin Layers ◽  
Glass Layer ◽  
Hydrogen Atoms ◽  
Surface Layers ◽  
Ion Beam Assisted Deposition ◽  
Metal Metal

ABSTRACTDepth profiles of elements in the surface layers of metals and metallized dielectrics were investigated by Rutherford Backscatteríng Spectrometry (RBS) (for the depth profiling of heavy elements), resonant elastic Backscattering Spectrometry (BS) of 4He+ and 1H+ (for the light elements depth profiling), Elastic Recoil Detection (ERD) of 1H+ (for depth profiling of hydrogen atoms), SIMS and AES techniques. The technological TAMEK source operated in the regime of ion beam assisted deposition (IBAD) of the metal ions (ion implantation at average beam energy ≤ 150 KeV and simultaneous deposition of the same ions at energy 100 eV) in pulse mode. Coatings were deposited on metal and glass samples at temperature of substrates T=100° C. In this report, we discuss the investigation results of samples modified by IBAD in technical vacuum produced by oil diffusion pumping. Phases like TiO, TiC, TiN, TiH are indicated in interface coating-substrate layers. The total thickness of mutually mixed metal-glass layer was found to be 400 nm and it was equal up to 3 µm for metal-metal layers. Cu/Al thin layers on a glass subsrate may be used as mirrors for powerful lasers with large (up to 5 J/cm2) energy contribution.

Tracer diffusion of 60Co and 63Ni in amorphous NiZr alloy

1988 ◽  
Vol 3 (1) ◽  
pp. 55-58 ◽  
Author(s):  
K. Hoshino ◽  
R. S. Averback ◽  
H. Hahn ◽  
S. J. Rothman
Keyword(s):  
Amorphous Alloy ◽  
Temperature Dependence ◽  
Ion Beam ◽  
Tracer Diffusion ◽  
Rutherford Backscattering ◽  
Equiatomic Composition ◽  
Serial Sectioning ◽  
Arrhenius Behavior ◽  
Temperature Range ◽  
Good Agreement

Tracer diffusion of 60Co and 63Ni in the amorphous alloy NiZr near the equiatomic composition has been measured in the temperature range between 486 and 641 K using the ion-beam sputter-sectioning technique for serial sectioning. The temperature dependence for the diffusivities of Co and Ni in a-NiZr exhibit Arrhenius behavior; these can be expressed as follows: D∗co = 3.6 × 10−7 exp [− (135 ± 14) kJ mol−1 /RT] m2/s and D∗Ni = 1.7 × 10−7 exp [− (140 ± 9) kJ mol−1 /RT] m2/s. The values of D∗Ni are in good agreement with those measured by the Rutherford backscattering technique. The measured diffusivities were independent of time, indicating that no relaxation took place during diffusion.

Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

1992 ◽  
Vol 50 (2) ◽  
pp. 1132-1133
Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Incidence Angle ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Ion Beams ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trace Impurities ◽  
Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

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