Probing the Miscibility Gap of the Pt–Pd Binary System by Atom Probe Tomography

To solve the uncertainty of the platinum (Pt)–palladium (Pd) phase diagram, especially the existence of a suggested miscibility gap, atom probe tomography (APT) was used to determine the time evolution of the composition after heat treatment. Due to the extraordinarily slow diffusion in the temperature range of the controversial phase separation, the investigated volume was limited to nano-sized multiple layers deposited by ion beam sputtering (IBS). The evaporated volume was reconstructed from the obtained datasets and the respective diffusion coefficients were determined using the Fourier series solution of the diffusion equation. Beginning with pure Pt and Pd layers annealed at 673, 773, 873, and 973 K, the mixing appears to be purely diffusion controlled in the chosen annealing times, but the state of complete mixing was still not observed. Therefore, extended isothermal annealing sequences at 673 and 773 K with pre-alloyed layers have been carried out. They clearly suggest complete mixing even at the lowest investigated temperatures.

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Atom Probe Study of the Miscibility Gap in CuNi Thin Films and Microstructure Development

Microscopy and Microanalysis ◽

10.1017/s1431927621012988 ◽

2021 ◽

pp. 1-11

Author(s):

Rüya Duran ◽

Patrick Stender ◽

Sebastian Manuel Eich ◽

Guido Schmitz

Keyword(s):

Focused Ion Beam ◽

Isothermal Annealing ◽

Ion Beam ◽

Atom Probe ◽

Miscibility Gap ◽

Ion Beam Sputtering ◽

Beam Sputtering ◽

Nonequilibrium States ◽

Composition Profiles

Abstract The unclear miscibility of CuNi alloys was investigated with atom probe tomography (APT). Multilayered thin film samples were prepared by ion beam sputtering (IBS) and focused ion beam (FIB) shaping. Long-term isothermal annealing treatments in a UHV furnace were conducted at temperatures of 573, 623, and 673 K to investigate the mixing process. The effective interdiffusion coefficient of the nanocrystalline microstructure (including defect diffusion) was determined to be Deff = 1.86 × 10−10 m2/s × exp(−164 kJ/mol/RT) by fitting periodic composition profiles through a Fourier series. In nonequilibrium states, microstructural defects like grain boundaries and precipitates were observed. While at the two higher temperatures total mixing is observed, a clear experimental evidence is found for a miscibility gap at 573 K with the boundary concentrations of 26 and 66 at%. These two compositions are used in a subregular solution model to reconstruct the phase miscibility gap. So, the critical temperature TC of the miscibility gap is found to be 608 K at a concentration of 45 at% Ni.

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Self-Diffusion in Magnetron-Sputtered Nanocrystalline Fe Films

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.11.13 ◽

2010 ◽

Vol 11 ◽

pp. 13-18 ◽

Cited By ~ 3

Author(s):

S. Chakravarty ◽

U. Tietze ◽

D. Lott ◽

M. Horisberger ◽

Jochen Stahn ◽

...

Keyword(s):

Point Defects ◽

Isothermal Annealing ◽

Diffusion Length ◽

Ion Beam ◽

Neutron Reflectometry ◽

Time Dependent ◽

Ion Beam Sputtering ◽

Self Diffusion ◽

Good Accordance ◽

Beam Sputtering

Self-diffusion in magnetron sputtered nanocrystalline Fe films was investigated by neutron reflectometry on [natFe(10 nm)/57Fe(5 nm)]20 isotope multilayers between 310 and 510°C. The determined diffusivities corresponding to diffusion length between 0.8 – 2.1 nm are time dependent and decrease by more than two orders of magnitude during isothermal annealing. This behaviour can be attributed due to the annihilation of frozen-in point defects, formed during sputtering. For very long annealing times of more than 8 days the diffusivities above 400°C are in good accordance with the volume diffusivities on single crystals given in the literature. However, at temperatures below 400°C the diffusivities are higher than extrapolated literature data, indicating that defect annihilation is still an ongoing process. Furthermore, a comparison of diffusivities obtained for nanocrystalline Fe films prepared by magnetron sputtering and ion beam sputtering, respectively, is presented and discussed.

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Measurement of small diffusion coefficients using ion-beam-sputtering as a microsectioning technique

Journal of Nuclear Materials ◽

10.1016/0022-3115(78)90269-6 ◽

1978 ◽

Vol 69-70 ◽

pp. 545-548 ◽

Cited By ~ 21

Author(s):

H. Mehrer ◽

K. Maier ◽

G. Hettich ◽

H.J. Mayer ◽

G. Rein

Keyword(s):

Diffusion Coefficients ◽

Ion Beam ◽

Ion Beam Sputtering ◽

Small Diffusion ◽

Beam Sputtering

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Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071053 ◽

1973 ◽

Vol 31 ◽

pp. 122-123

Author(s):

J. S. Maa ◽

Thos. E. Hutchinson

Keyword(s):

Epitaxial Growth ◽

Film Growth ◽

Ion Beam ◽

Ion Beam Sputtering ◽

Microscopy Technique ◽

Direct Observations ◽

In Situ Electron Microscopy ◽

Beam Sputtering ◽

The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

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TEM Study of Co/Pd and Co/Au Multilayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151015 ◽

1993 ◽

Vol 51 ◽

pp. 1036-1037

Author(s):

A.E.M. De Veirman ◽

F.J.G. Hakkens ◽

W.M.J. Coene ◽

F.J.A. den Broeder

Keyword(s):

Magnetic Anisotropy ◽

Ion Beam ◽

Perpendicular Magnetic Anisotropy ◽

Optical Recording ◽

Magnetic Multilayer ◽

Ion Beam Sputtering ◽

Cross Sectional ◽

Transmission Electron ◽

Beam Sputtering ◽

Substrate Temperatures

There is currently great interest in magnetic multilayer (ML) thin films (see e.g.), because they display some interesting magnetic properties. Co/Pd and Co/Au ML systems exhibit perpendicular magnetic anisotropy below certain Co layer thicknesses, which makes them candidates for applications in the field of magneto-optical recording. It has been found that the magnetic anisotropy of a particular system strongly depends on the preparation method (vapour deposition, sputtering, ion beam sputtering) as well as on the substrate, underlayer and deposition temperature. In order to get a better understanding of the correlation between microstructure and properties a thorough cross-sectional transmission electron microscopy (XTEM) study of vapour deposited Co/Pd and Co/Au (111) MLs was undertaken (for more detailed results see ref.).The Co/Pd films (with fixed Pd thickness of 2.2 nm) were deposited on mica substrates at substrate temperatures Ts of 20°C and 200°C, after prior deposition of a 100 nm Pd underlayer at 450°C.

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Nanocrystalline silicon ( nc-Si ) from single ion beam sputtering

MRS Proceedings ◽

10.1557/proc-762-a7.3 ◽

2003 ◽

Vol 762 ◽

Cited By ~ 1

Author(s):

Z.B. Zhou ◽

G.M. Hadi ◽

R.Q. Cui ◽

Z.M. Ding ◽

G. Li

Keyword(s):

Solar Cell ◽

Ion Beam ◽

Nanocrystalline Silicon ◽

Silicon Films ◽

Chamber Pressure ◽

Ion Beam Sputtering ◽

High Hydrogen ◽

Beam Sputtering ◽

Si Films ◽

Nanocrystalline Silicon Films

AbstractBased on a small set of selected publications on the using of nanocrystalline silicon films (nc-Si) for solar cell from 1997 to 2001, this paper reviews the application of nc-Si films as intrinsic layers in p-i-n solar cells. The new structure of nc-Si films deposited at high chamber pressure and high hydrogen dilution have characters of nanocrystalline grains with dimension about several tens of nanometer embedded in matrix of amorphous tissue and a high volume fraction of crystallinity (60~80%). The new nc-Si material have optical gap of 1.89 eV. The efficiency of this single junction solar cell reaches 8.7%. This nc-Si layer can be used not only as an intrinsic layer and as a p-type layer. Also nanocrystalline layer may be used as a seed layer for the growth of polycrystalline Si films at a low temperature.We used single ion beam sputtering methods to synthesize nanocrystalline silicon films successfully. The films were characterized with the technique of X-ray diffraction, Atomic Force Micrographs. We found that the films had a character of nc-amorphous double phase structure. Conductivity test at different temperatures presented the transportation of electrons dominated by different mechanism within different temperature ranges. Photoconductivity gains of the material were obtained in our recent investigation.

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Formation of Luminescent Si Nanocrystals by High-Temperature Annealing of Ion-Beam-Sputtered Si/SiO2 Multilayers

MRS Proceedings ◽

10.1557/proc-775-p9.57 ◽

2003 ◽

Vol 775 ◽

Author(s):

Suk-Ho Choi ◽

Jun Sung Bae ◽

Kyung Jung Kim ◽

Dae Won Moon

Keyword(s):

Quantum Confinement ◽

Radiative Recombination ◽

Ion Beam ◽

Quantum Confinement Effect ◽

Visible Range ◽

Ion Beam Sputtering ◽

Transmission Electron ◽

Si Nanocrystals ◽

Beam Sputtering ◽

Microscopy Images

AbstractSi/SiO2 multilayers (MLs) have been prepared under different deposition temperatures (TS) by ion beam sputtering. The annealing at 1200°C leads to the formation of Si nanocrystals in the Si layer of MLs. The high resolution transmission electron microscopy images clearly demonstrate the existence of Si nanocrystals, which exhibit photoluminescence (PL) in the visible range when TS is ≥ 300°C. This is attributed to well-separation of nanocrystals in the higher-TS samples, which is thought to be a major cause for reducing non-radiative recombination in the interface between Si nanocrystal and surface oxide. The visible PL spectra are enhanced in its intensity and are shifted to higher energy by increasing TS. These PL behaviours are consistent with the quantum confinement effect of Si nanocrystals.

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