Solid-state amorphization, interdiffusion, and ion-beam mixing in Au/Zr and Ni/Zr

1989 ◽  
Vol 4 (6) ◽  
pp. 1444-1449 ◽  
Author(s):  
Fu-Rong Ding ◽  
P. R. Okamoto ◽  
L. E. Rehn

Inert-gas markers, Rutherford backscattering, and x-ray diffraction were used to investigate solid-state interdiffusion in Ni/Zr and Au/Zr bilayer films as a function of temperature; microstructural studies during annealing were performed in situ, in a high-voltage electron microscope. Au, in contrast to Ni, is not an anomalously fast diffuser in crystalline Zr. Nevertheless, an amorphous product phase was found in both alloy systems for reaction temperatures  550 K; heterogeneous nucleation of the amorphous phase was observed in Au/Zr. The interdiffusion data reveal two distinct Arrhenius regimes, 330–∼470 K and ∼480–550 K, with quite different apparent activation enthalpies. These thermal interdiffusion results are compared with temperature dependent studies of ion-beam mixing in similar bilayer specimens. This comparison indicates that the enhanced efficiencies observed for ion-beam mixing above ∼480 K result from the as-prepared metastable microstructurc, and are not due to radiation-enhanced diffusion.

1988 ◽  
Vol 128 ◽  
Author(s):  
Udo Scheuer ◽  
Lynn E. Rehn ◽  
Pete Baldo

ABSTRACTCrystalline Fe and Fe-10at.%Ti and amorphous Fe-37at.%Ti films with Ag and Hf markers were produced by vapor deposition. Marker spreading during ion-beam mixing between 77 K and 580 K was measured using Rutherford Back-scattering (RBS). Marker spreading was also measured between temperatures of 300 K to 700 K after full crystallization of the Fe-37at.%Ti films. Microstructural changes during ion-beam mixing were studied in situ, in a High-Voltage Electron Microscope. Homogeneous nucleation of a metastable bcc phase, was observed at high temperatures. The results are discussed in terms of their relevance to “radiation-enhanced” diffusion in amorphous materials.


1988 ◽  
Vol 100 ◽  
Author(s):  
Fu-Rong Ding ◽  
P. R. Okamoto ◽  
L. E. Rehn

ABSTRACTAu/Zr bilayer films with inert-gas markers were produced by low energy (< 4 keV) implantation. Mass transport was measured during ion-beam mixing with 1 MeV Kr at several temperatures between 330 and 540K. Two distinct regimes of apparent Arrhenius behavior were found with activation enthalpies of 0.06 and 0.9 eV in the temperature range 330–440K and 460–540K, respectively. Microstructural changes during ion-beam mixing were studied in situ, in a high voltage electron microscope. Heterogeneous nucleation of an amorphous phase was observed during mixing. The results are compared with similar studies reported previously in Ni/Zr bilayer specimens.


1989 ◽  
Vol 157 ◽  
Author(s):  
H.K. Kim ◽  
J.H. Song ◽  
S.K. Kim ◽  
K. Jeong ◽  
C.N. Whang ◽  
...  

ABSTRACTIon beam mixing of a Pd/Cu bilayer is studied using irradiation with 80 keV Ar+ ions at room temperature. RBS analysis shows that intermixing has occurred across the Pd/Cu interface, and that the mixing amount increases with increasing ion dose, which agrees well with a model for radiation enhanced diffusion. It is found that the Cu3Pd phase grows in a layer-by-layer manner.


1987 ◽  
Vol 93 ◽  
Author(s):  
M. Nastasi ◽  
J. R. Tesmer ◽  
J.-P. Hirvonen

ABSTRACTBilayer samples of Ti/C and Fe/C have been ion beam mixed with 400 keV Xe ions to a dose of 1 × 1016 ions/cm2. Mixing experiments were performed at 77, 300, 573, and 723 K. The transition between the temperature independent and temperature dependent mixing occurred between 300 and 573 K in Fe/C samples and between 573 and 723 in Ti/C sample. In the temperature independent mixing regime mixing is reasonably well explained by a thermodynamic model of ion mixing while at higher temperatures a radiation enhanced diffusion mechanism is evident.


1985 ◽  
Vol 54 ◽  
Author(s):  
AH. Van Ommen ◽  
M.F.C. Willemsen ◽  
PR. Boudewijn ◽  
A. H. Reader

ABSTRACTWe studied ion beam mixing of thin Mo films on monocrystalline Si by As “implantation at room temperature. The results differ significantly from those obtained for implantation at elevated temperature (T > 200°C). where ion beam mixing results in hexagonal MoSi2 formation. Room temperature implantation results in the formation of an amorphous mixed layer. The composition of this layer varies with depth from Mo-rich to Si-rich. The mixed layer thickness increases linearly with implanted dose and energy. An increase of the implantation temperature with 100°C gives rise to a factor of 2 larger mixed layer thickness and to the formation of amorphous MoSi2 near the interface with Si. These phenomena indicate that at elevated temperature ion beam mixing is controlled by radiation-enhanced diffusion whereas, at room temperature ballistic mixing is the dominant mechanism.


1983 ◽  
Vol 27 ◽  
Author(s):  
M. B. Lewis ◽  
C. J. Mchargue

ABSTRACTThe ion beam mixing technique has been employed to mix metal atoms into the surface layers of Al2O3. Ion beams of Fe+ and Zr+ in the 1 to 4 MeV energy range were used to irradiate Al2O3 specimens on the surfaces of which films of chromium or zirconium had been evaporated. Some specimens were irradiated at elevated temperatures of 873 or 1173 K. Rutherford backscattering (RBS) and channeling methods were used to measure the metal atom depth profiles near the surface. Analyses of the backscattering data included binary collision calculations using the codes TRIM and MARLOWE. The significance and limitations of high energy (>1 MeV) beams for ion beam mixing experiments is discussed. Evidence was found for radiation enhanced diffusion and/or solubility of zirconium and chromium in Al2O3 at 873 K.


Author(s):  
K. Neubeck ◽  
C.-E. Lefaucheur ◽  
H. Hahn ◽  
A.G. Balogh ◽  
H. Baumann ◽  
...  

1996 ◽  
Vol 11 (5) ◽  
pp. 1277-1283 ◽  
Author(s):  
K. Neubeck ◽  
H. Hahn ◽  
A. G. Balogh ◽  
H. Baumann ◽  
K. Bethge ◽  
...  

Ion beam mixing, diffusion properties, and phase stability have been investigated in Cu/Al2O3 bilayer samples. Specimens were prepared by vapor deposition and irradiated with 150 keV Ar+ ions up to a fluence of 1.5 · 1017 Ar+/cm2. Sample temperature under irradiation was varied between 77 K and 673 K. The mixing behavior was studied by analyzing the concentration depth profiles, determined by Rutherford Backscattering Spectroscopy. It was found that mixing efficiencies of Cu, Al, and O scale with Ar+ fluence. Radiation enhanced diffusion (RED), observed above room temperature, is separated from ballistic mixing and high temperature diffusion. The migration enthalpy for interdiffusion in the RED region (between RT and 300 °C) was estimated to be approximately 0.3 eV. Sputtering yields depending on temperature gradient near to sample and phase stability versus ion dose and temperature are also discussed.


Sign in / Sign up

Export Citation Format

Share Document