Grain Growth in Polycrystalline Thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
Carl V. Thompson
Keyword(s):  
Thin Films ◽  
Grain Growth ◽  
Energy Minimization ◽  
Film Formation ◽  
Interface Energy ◽  
Surface And Interface ◽  
Grain Sizes ◽  
Thermal Expansion Coefficients ◽  
Average Grain Size ◽  
Strain Energy Minimization

ABSTRACTThe performance and reliability of polycrystalline films are strongly affected by the average grain size and the distribution of grain sizes and orientations. These are often controlled through grain growth phenomena which occur during film formation and during subsequent processing. Abnormal rather than normal grain growth is most common in thin films, and leads to an evolution in the distribution of grain orientations as well as grain sizes, often leading to uniform or restricted crystallographic orientations or textures. Surface and interface energy minimization and strain energy minimization can lead to development of different textures, depending on which is dominant. The final texture resulting from grain growth depends on the film thickness, the deposition temperature, the grain growth temperature, the thermal expansion coefficients of the film and substrate, and the mechanical properties of the film, as well as other factors.

Computer Simulation of Strain Energy and Surface- and Interface-Energy on Grain Growth in Thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
R. Carel ◽  
C. V. Thompson ◽  
H. J. Frost
Keyword(s):  
Thin Films ◽  
Grain Growth ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Driving Forces ◽  
Interface Energy ◽  
Orientation Dependence ◽  
Surface And Interface ◽  
Elastic Regime ◽  
Strained Films

ABSTRACTWe have simulated strain energy effects and surface- and interface-energy effects on grain growth in thin films, using properties of polycrystalline Ag (p-Ag) on single crystal (001) Ni on (001) MgO for comparison with experiments. Surface- and interface-energy and strain energy reduction drive the growth of grains of specific crystallographic orientations. The texture that will result when grain growth has occurred minimizes the sum of these driving forces. In the elastic regime, strain energy density differences result from the orientation dependence of the elastic constants of the biaxially strained films. In the plastic regime, strain energy also depends on grain diameter and film thickness. In p-Ag/(001) Ni, surface- and interface-energy minimization favors Ag grains with (11) texture. In the absence of a grain growth stagnation, the texture at later times is always (111). However, for high enough strains and large enough thicknesses, the strain energy driving force can favor a (001) texture at early times, which reverts to a (111) texture at later times, once the grains have yielded.

Texture Maps for Orientation Evolution During Grain Growth in Thin Films

1995 ◽  
Vol 403 ◽  
Author(s):  
Steven C. Seel ◽  
Roland Carel ◽  
Carl V. Thompson
Keyword(s):  
Thin Films ◽  
Grain Growth ◽  
Strain Energy ◽  
Driving Forces ◽  
Chemical Vapor ◽  
Interface Energy ◽  
Fcc Metals ◽  
Surface And Interface ◽  
Different Temperatures ◽  
Energy Anisotropy

AbstractOrientation selective grain growth in thin films arises due to anisotropy in materials properties. For continuous thin films, there are at least two orientation dependent driving forces for grain growth: (i) surface and interface energy anisotropy; (ii) strain energy anisotropy (both elastic and plastic). In fcc metals, the preferred growth of grains with (111) texture occurs due to their low surface and interface energy. Stresses in thin films arise during deposition and as a result of post-deposition annealing. A texture dependence of strain energy density arises in biaxially strained thin films due to anisotropy of elastic properties and/or orientation-dependent yield stresses. For most fcc metals, the strain energy driving force promotes the growth of (001) grains due to minimization of the combined elastic and plastic strain energy. The magnitudes of the orientation dependent driving forces for grain growth depend on the characteristics and processing conditions of the film and substrate. We have performed grain growth experiments for Ag films on single crystal Ni on MgO; Ag films on plasma-enhanced chemical vapor deposited (PECVD) SiO2 on MgO; Ag films on oxidized Si; and Ni films on oxidized Si. The texture resulting from grain growth in films of different thicknesses and deposited at different temperatures were determined, and the results are presented in the form of texture maps. The texture which dominates as a result of grain growth can be understood through the use of texture maps and compares well with analytic models for texture development during grain growth in thin films.

Nanostructure Evolution of ZnO in Ultra-fast Microwave Sintering

2011 ◽  
Vol 691 ◽  
pp. 65-71 ◽  
Author(s):  
Rodolfo F. K. Gunnewiek ◽  
Ruth Herta Goldsmith Aliaga Kiminami
Keyword(s):  
Grain Size ◽  
Zinc Oxide ◽  
Grain Growth ◽  
Microwave Sintering ◽  
High Heating Rate ◽  
Heating Rates ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Conventional Sintering ◽  
Holding Temperature

Grain growth is inevitable in the sintering of pure nanopowder zinc oxide. Sintering depend on diffusion kinetics, thus this growth could be controlled by ultra-fast sintering techniques, as microwave sintering. The purpose of this work was to investigate the nanostructural evolution of zinc oxide nanopowder compacts (average grain size of 80 nm) subjected to ultra-rapid microwave sintering at a constant holding temperature of 900°C, applying different heating rates and temperature holding times. Fine dense microstructures were obtained, with controlled grain growth (grain size from 200 to 450nm at high heating rate) when compared to those obtained by conventional sintering (grain size around 1.13µm), which leads to excessively large average final grain sizes.

Ion Induced Grain Growth in Pd

1991 ◽  
Vol 235 ◽  
Author(s):  
D. A. Lilienfeld ◽  
P. Bøorgesen ◽  
P. Meyer
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Low Temperatures ◽  
Nanocrystalline Materials ◽  
Ion Irradiation ◽  
Size Distributions ◽  
Careful Choice ◽  
Average Grain Size

ABSTRACTIon irradiation induced grain growth size distributions in Pd are examined at low temperatures. Two features are observed: 1) A majority of the grains saturate in size. 2) Some grains achieve sizes much larger than the average grain size and continue to grow with ion dose. However, by careful choice of ion mass and ion dose, it is possible to produce a sample possessing a monomodal grain size. This process will have applications in producing thin films of nanocrystalline materials.

Correlation of the Stress-Temperature History with Microstructure in A1-0.5Cu and A1-0.15Pd Thin Films

1994 ◽  
Vol 356 ◽  
Author(s):  
D. D. Knorr ◽  
K.P. Rodbell
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Substrate Temperature ◽  
Grain Growth ◽  
Room Temperature ◽  
Temperature History ◽  
Thermal Expansion Mismatch ◽  
Grain Sizes ◽  
Substrate Temperatures ◽  
Precipitate Structure

AbstractBlanket films (1 μm thick) of both A1-0.5Cu and A1-0.15Pd were deposited at room temperature, 150°C, and 300°C. Stress in the as-deposited wafers increased with substrate temperature, as expected from the thermal expansion mismatch on cooling. All conditions were tiicrmally cycled to 450°C three times while continuously monitoring stress. The shapes of the curves were different for the two alloys because precipitates dissolve and reprecipitate in AlCu, but are present over the entire temperature range in AlPd. Lesser differences were evident comparing the stress-temperature behavior for the various substrate temperatures within a single alloy. The precipitate structure also influences the grain growth during thermal cycling, where substantially larger median grain sizes are found in AlCu compared to AlPd.

Energy Minimization During Epitaxial Grain Growth: Strain VS. Interfacial Energy

1993 ◽  
Vol 317 ◽  
Author(s):  
J. A. Floro ◽  
R. Carel ◽  
C. V. Thompson
Keyword(s):  
Grain Growth ◽  
Interfacial Energy ◽  
Energy Minimization ◽  
Strain Energy ◽  
Elastic Anisotropy ◽  
Interface Energy ◽  
Growth Strain ◽  
Free Energies ◽  
Film Substrate ◽  
Epitaxial Grain Growth

ABSTRACTWe have investigated Epitaxial Grain Growth (EGG) in polycrystalline Ag films on Ni (001) substrates. EGG is driven by minimization of crystallographically anisotropie free energies such as the film/substrate interfacial energy and the film strain. Under some conditions EGG results in the preferred growth of the (111) epitaxial orientations that are predicted to minimize the interfacial energy. However, when Ag films are deposited on Ni (001) at low temperature, EGG experiments consistently find that (111) oriented grains are consumed by grains with (001) orientations predicted to have much higher interface and surface energy. The large elastic anisotropy of Ag can account for this discrepancy. The film thickness and the deposition temperature (relative to the grain growth temperature) determine whether strain energy or interface energy minimization dominates orientation evolution during grain growth.

Competition between strain and interface energy during epitaxial grain growth in Ag films on Ni(001)

1994 ◽  
Vol 9 (9) ◽  
pp. 2411-2424 ◽  
Author(s):  
J.A. Floro ◽  
C.V. Thompson ◽  
R. Carel ◽  
P.D. Bristowe
Keyword(s):  
Surface Energy ◽  
Grain Growth ◽  
Interfacial Energy ◽  
Elastic Anisotropy ◽  
Interface Energy ◽  
Orientation Dependence ◽  
Embedded Atom ◽  
Strain Energy Minimization ◽  
Film Substrate ◽  
Epitaxial Grain Growth

Epitaxial Grain Growth (EGG) is an orientation-selective process that can occur in polycrystalline thin films on single crystal substrates. EGG is driven by minimization of crystallographically anisotropic free energies. One common driving force for EGG is the reduction of the film/substrate interfacial energy. We have carried out experiments on polycrystalline Ag films on Ni(001) substrates. The orientation dependence of the Ag/Ni interfacial energy has been previously calculated using the embedded atom method. Under some conditions, EGG experiments lead to the (111) orientations calculated to be interface- and surface-energy-minimizing. However, when Ag films are deposited on Ni(001) at low temperature, EGG experiments consistently find that (111) oriented grains are consumed by grains with (001) orientations predicted to have much higher interface and surface energy. The large elastic anisotropy of Ag can account for this discrepancy. Strain energy minimization favors growth of (001) grains and can supersede minimization of interfacial energy if sufficient strain is present and if the film is initially unable to relieve the strain by plastic deformation.

One-step synthesis of Fe–Au core–shell magnetic-plasmonic nanoparticles driven by interface energy minimization

2019 ◽  
Vol 4 (6) ◽  
pp. 1326-1332 ◽  
Author(s):  
Anna Tymoczko ◽  
Marius Kamp ◽  
Christoph Rehbock ◽  
Lorenz Kienle ◽  
Elti Cattaruzza ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Energy Minimization ◽  
Interface Energy ◽  
Plasmonic Nanoparticles ◽  
Core Shell ◽  
One Step

The formation of core–shell (CS) nanoparticles (NPS) often requires complex procedures. Due to minimization of interface energy, we show that colloidal Fe–Au CS NPs are obtained in one step, by laser ablation of bimetallic thin films in liquid.

In Situ Observation of Grain Growth and Recrystallization of Steel at High Temperature

2010 ◽  
Vol 638-642 ◽  
pp. 1077-1082 ◽  
Author(s):  
Yasuhiro Yogo ◽  
Kouji Tanaka ◽  
Koukichi Nakanishi
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Grain Growth ◽  
In Situ Observation ◽  
Initial Structure ◽  
Grain Sizes ◽  
Dynamic Observation ◽  
Average Grain Size ◽  
Observation Method

An in-situ observation method for structures at high temperature is developed. The new observation device can reveal grain boundaries at high temperature and enables dynamic observation of these boundaries. Grain growth while maintaining microstructure at high temperature is observed by the new observation device with only one specimen for the entire observation, and grain sizes are quantified. The quantifying process reveals two advantages particular to the use of the new observation device: (1) the ability to quantify grain sizes of specified sizes and (2) the results of average grain size for many grains have significantly less errors because the initial structure is the same for the entire observation and the quantifying process. The new observation device has the function to deform a specimen while observing structures at high temperature, so that enables it to observe dynamic recrystallization of steel. The possibility to observe recrystallization is also shown.

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