scholarly journals Interdependence of stress and interdiffusion during solid-state amorphization in Ni–Hf

2000 ◽  
Vol 15 (2) ◽  
pp. 463-475 ◽  
Author(s):  
W. S. L. Boyer ◽  
M. Atzmon
Keyword(s):  
Solid State ◽  
Tensile Stress ◽  
Diffusion Couple ◽  
Amorphous Phase ◽  
Ion Irradiation ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Curvature Measurements ◽  
Stress Variations ◽  
State Amorphization

The evolution of stress in a Ni–Hf diffusion couple during solid-state amorphization reaction has been monitored by substrate curvature measurements and x-ray diffraction. The latter technique allowed an independent determination of the contribution of changes in stress-free lattice parameter to the stress in the crystalline layers. The results indicate that the amorphous phase forms under a large tensile stress, which relaxes as the reaction progresses. This stress in the amorphous phase is consistent with the volume change associated with the reaction. Stresses in the crystalline, elemental phases are considerably smaller and not affected by the reaction. Low-temperature Ni ion irradiation increases the tensile stress in the diffusion couple. The large observed stress variations are not accompanied by variations in the effective interdiffusion coefficient.

Interdiffusion and Stress Evolution During Solid-State Amorphization in Ni-Hf Thin-Film Diffusion Couples

1995 ◽  
Vol 400 ◽  
Author(s):  
M. Atzmon ◽  
W. S. L. Boyer
Keyword(s):  
Solid State ◽  
Tensile Stress ◽  
Diffusion Couple ◽  
Rutherford Backscattering Spectrometry ◽  
Amorphous Layer ◽  
Stress Evolution ◽  
Curvature Measurements ◽  
Thin Film Diffusion ◽  
Stress Variations ◽  
State Amorphization

AbstractUsing a combination of x-ray diffraction and curvature measurements, the stress evolution during solid-state amorphization in a Ni-Hf diffusion couple has been monitored. In contrast to the Co-Hf system, no dissolution of Ni in Hf is observed. During interdiffusion, the growing amorphous layer develops a large tensile stress, which subsequently relaxes by creep. Irradiation of the diffusion couple leads to an increase in tensile stress, and a further increase following a subsequent anneal. Composition measurements by Rutherford backscattering spectrometry indicate absence of an effect of the stress variations on the effective interdiffusion coefficient.

Solid-state amorphization reaction by temperature-dependent ion mixing

1989 ◽  
Vol 4 (6) ◽  
pp. 1299-1302 ◽  
Author(s):  
E. Ma ◽  
C. W. Nieh ◽  
M-A. Nicdlet ◽  
W. L. Johnson
Keyword(s):  
Solid State ◽  
Long Range ◽  
Amorphous Phase ◽  
Ion Irradiation ◽  
Al Alloy ◽  
Temperature Dependent ◽  
Compound Formation ◽  
State Amorphization

A layer of amorphous Mo–Al alloy is formed by ion-assisted solid-state interdiffusion reaction of a Mo/Al bilayer. Xe ion irradiation at 200 °C enhances the long-range diffusion of the dominant moving species while the formation of equilibrium compounds remains inhibited. The idea of using the temperature-dependent ion mixing at intermediate temperatures to promote a solid-state amorphization reaction opens the possibility of growing an amorphous phase in a system where both compound formation and interdiffusion are difficult

Solid state amorphization reactions in deformed Ni-Zr multilayered composites

1990 ◽  
Vol 5 (3) ◽  
pp. 488-497 ◽  
Author(s):  
G. C. Wong ◽  
W. L. Johnson ◽  
E. J. Cotts
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Amorphous Phase ◽  
Equilibrium Phase ◽  
Solid State Reactions ◽  
Heat Of Mixing ◽  
Scanning Calorimetry ◽  
Multilayered Composites ◽  
State Amorphization ◽  
Thermal Stability Of

The mechanisms of metallic glass formation and competing crystallization processes in mechanically-deformed Ni-Zr multilayered composites have been investigated by means of differential scanning calorimetry and x-ray diffraction. Our investigation of the heat of formation of amorphous NixZr1−x alloys shows a large negative heat of mixing (on the order of 30 kJ/mole) for compositions near Zr55Ni45 with a compositional dependence qualitatively similar to that predicted by mean field theory. We find that the products of solid state reactions in composites of Ni and Zr can be better understood in terms of the equilibrium phase diagram and the thermal stability of liquid quenched metallic glasses. We have determined the composition of the growing amorphous phase at the Zr interface in these Ni-Zr diffusion couples to be 55 ± 4% Zr. We investigated the kinetics of solid state reactions competing with the solid state amorphization reaction and found the value of the activation energy of the initial crystallization and growth of the growing amorphous phase to be 2.0 ± 0.1 eV, establishing an upper limit on the thermal stability of the growing amorphous phase.

A Review of X-Ray Diffraction Methods for Diffusion Studies

1973 ◽  
Vol 17 ◽  
pp. 395-415
Author(s):  
J. A. Carpenter ◽  
D. R. Tenney
Keyword(s):  
Solid State ◽  
Lattice Parameter ◽  
Solid State Diffusion ◽  
X Ray Diffraction ◽  
X Ray ◽  
State Diffusion ◽  
Diffusion Studies ◽  
Parameter Spread ◽  
Non Destructive

AbstractX-ray diffraction methods for studying solid-state diffusion are reviewed. Because of the lack of penetration, such methods are suited for diffusion zones spanning only a few microns. Most involve analyses of one, or more, (hkl) “band” of intensities spread in 2θ as a result of the corresponding lattice parameter spread associated with compositional inhomogeneities. Further, many are non-destructive, making it possible to follow the progression of diffusion with time in the same specimen.

SOLID STATE AMORPHIZATION IN MECHANICALLY ALLOYED Al–Ti–Si NANOCOMPOSITES

2005 ◽  
Vol 04 (05n06) ◽  
pp. 1025-1028
Author(s):  
I. MANNA ◽  
P. NANDI ◽  
B. BANDYOPADHYAY ◽  
P. M. G. NAMBISSAN ◽  
K. GHOSHRAY ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Amorphous Solid ◽  
Positron Annihilation Spectroscopy ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
State Amorphization

The microstructural evolution at different stages of milling of a ternary powder blend of Al 50 Ti 40 Si 10 composition was monitored by X-ray diffraction, high-resolution transmission electron microscopy, positron annihilation spectroscopy and 27 Al nuclear magnetic resonance. Ball-milling leads to alloying, nanocrystallization and partial solid state amorphization, either followed or accompanied by strain-induced nucleation of nanocrystalline intermetallic phases from an amorphous solid solution.

Ion irradiation during a solid state amorphization reaction

1988 ◽  
Vol 97 ◽  
pp. 97-100 ◽  
Author(s):  
K. Pampus ◽  
J. Bøttiger ◽  
K. Dyrbye ◽  
B. Torp ◽  
K. Samwer
Keyword(s):  
Solid State ◽  
Ion Irradiation ◽  
State Amorphization

High resolution studies of the solid state amorphization reaction in the ZrCo system with the atom probe/field ion microscope

1994 ◽  
Vol 343 ◽  
Author(s):  
Susanne Schneider ◽  
Ralf Busch ◽  
Konrad Samwer
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Amorphous Phase ◽  
Rutherford Backscattering Spectrometry ◽  
Atom Probe ◽  
Nanometer Scale ◽  
Probe Field ◽  
Field Ion Microscope ◽  
State Amorphization

ABSTRACTThe atom probe/field ion microscope is introduced as a new powerful investigation device to study the early stages of the solid state amorphization reaction (SSAR). A bilayer of Zr and Co was condensed under UHV conditions on W wire tips and analyzed in a field ion microscope (FIM) combined with an atom probe (AP). The reaction of Co with Zr has been studied at room temperature. FIM pictures and AP analysis have shown that even at low temperatures an amorphous phase is formed at the Zr/Co interface and in the Zr grain boundaries. In these areas concentration profiles have been taken on a nanometer scale. Most likely, the extended solid solution of Co found in α- Zr grain boundaries causes the formation of the amorphous phase. Further, Rutherford backscattering spectrometry (RBS) suggests that even point defects and dislocations at the surface of an α- Zr single crystal are sufficient to initiate the SSAR between a polycrystalline Co layer vapour- deposited onto that single crystal.

Ion Irradiation During a Solid State Amorphization Reaction

1988 ◽  
pp. 97-100
Author(s):  
K. PAMPUS ◽  
J. BØTTIGER ◽  
K. DYRBYE ◽  
B. TORP ◽  
K. SAMWER
Keyword(s):  
Solid State ◽  
Ion Irradiation ◽  
State Amorphization

Micro/nanostructure observation of microwave-heated Fe3O4

2009 ◽  
Vol 24 (5) ◽  
pp. 1741-1747 ◽  
Author(s):  
Noboru Yoshikawa ◽  
Ziping Cao ◽  
Dmitri Louzguin ◽  
Guoqiang Xie ◽  
Shoji Taniguchi
Keyword(s):  
Amorphous Phase ◽  
Single Mode ◽  
Lattice Parameter ◽  
State University ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Penn State ◽  
Local Transport ◽  
O Phase ◽  
Amorphous Phase Formation

To investigate the microwave (MW) processing of Fe3O4, for which occurrence of decrystallization has been reported, the micro/nanostructures of MW-heated Fe3O4 powder were observed in this study. The specimens were irradiated by 2.45 GHz MW at the position of magnetic (H)-field maximum in a TE10 single mode applicator. The specimen was heated well above the Curie temperature in H-field. The heated specimen above 1000 °C revealed the glass-like surface with the diminished x-ray diffraction (XRD) peak intensities. They resemble the reported features of decrystallization in an earlier work performed at Penn State University. According to the XRD profiles of the MW-heated specimens, formation of FeO and shift of Fe3O4 peaks to the lower angle with the broadened width were observed. To account for the findings, a model is presented that phase separation occurred into FeO and Fe3O4 resulting in an increased lattice parameter due to the increased oxygen content. This activity is caused by local transport of oxygen in nanoscale. Considering the shape of the main XRD Fe3O4 peak with a shoulder and the existence of halo in nanobeam diffraction (NBD), amorphous phase areas exist. As a result of transmission electron microscopy observation, it was shown that they were in nanoscaled localized regions, and it was not confirmed that the glass-like morphologies (or decrystallized morphologies) are totally amorphous. The observed micro/nanostructures and mechanism of the amorphous phase formation were discussed considering the Fe-O phase diagram.

X-ray powder diffraction and magnetic study of nominal Zn1-xNdxCr2Se4 – compounds (x = 0.05, 01)

2013 ◽  
Vol 28 (S2) ◽  
pp. S75-S85
Author(s):  
Izabela Jendrzejewska ◽  
Paweł Zajdel ◽  
Ewa Maciążek ◽  
Maria Sozańska ◽  
Tomasz Goryczka
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Powder Diffraction ◽  
Magnetic Moments ◽  
Solubility Limit ◽  
Lattice Parameter ◽  
Antiferromagnetic Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Matrix

Polycrystalline compounds in the Zn1-xNdxCr2Se4 system were prepared by solid state reaction using selenides (ZnSe, Cr2Se3) and pure elements (Nd, Se) as starting materials. The structural properties were determined by X-ray diffraction and the chemical composition confirmed by SEM-EDX. The observed symmetry is cubic, space group Fd3m, while the lattice parameter varies from 10.4955(7)Å to 10.4976(7)Å, and is larger than for the pure matrix. The solubility limit for the current synthesis route lies below x = 0.1. The magnetic moments, effective and saturation, increase with increasing amount of Nd ions. The Neel temperature TN and ΘCW drop, respectively, to 17.4K and 81K for x = 0.1, independently indicating that neodymium is incorporated into the spinel lattice and promotes antiferromagnetic coupling between the Cr3+ ions.

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