Grain Growth in Al-(Cu, Pd, Nb) Thin Films

1993 ◽  
Vol 309 ◽  
Author(s):  
J.D. Mis ◽  
K.P. Rodbell
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Weight Percent ◽  
Size Distributions ◽  
Precipitate Morphology ◽  
X Ray ◽  
Transmission Electron ◽  
Grain Size Distributions

AbstractThe microstructure of 1 μim thick Al films containing 0.5 and 2%Cu (weight percent), 0.3%Pd, and 0.3%Pd-0.3%Nb were investigated by transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS) as a function of isochronal and isothermal anneals. The grain size, grain size distribution, and precipitate morphology of these films was measured from 200 to 500ºC, with the activation energy for grain growth (Ea) determined for I h anneals at 200, 300, 400 and 500ºC. Normal grain growth was recorded for the A1Cu films annealed at temperatures ≤400ºC; however secondary grain growth occurred in the AI-2Cu film annealed for I h at 500ºC, with grains as large as 16 μm in diameter observed. Grain growth in the AI-0.3Pd films resulted in strongly bi-modal grain size distributions, with the onset ofsignificant grain growth retarded for I h anneals at temperatures ≤300ºC.The addition of Nb to the AI-0.3Pd film resulted in monomodal grain size distributions over the entire temperature range. The role of crystallographic texture on grain growth in thin films is discussed.

Grain growth and texture development in lithium fluoride thin films

2008 ◽  
Vol 23 (2) ◽  
pp. 452-462 ◽  
Author(s):  
Hakkwan Kim ◽  
Alexander H. King
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Growth ◽  
Annealing Time ◽  
Lithium Fluoride ◽  
Dark Field ◽  
Texture Development ◽  
Size Distributions ◽  
Grain Size Distributions

We have studied grain-growth and texture development in polycrystalline lithium fluoride thin films using dark-field transmission electron microscopy. We demonstrate that we can isolate the size distribution of 〈111〉 surface normal grains from the overall size distribution, based on simple and plausible assumptions about the texture. The {111} texture formation and surface morphology were also observed by x-ray diffraction and atomic force microscopy, respectively. The grain-size distributions become clearly bimodal as the annealing time increases, and we deduce that the short-time size distributions are also a sum of two overlapping peaks. The smaller grain-size peak in the distribution corresponds to the {111}-oriented grains, which do not grow significantly, while all other grains increase in size with annealing time. A novel feature of the LiF films is that the {111} texture component strengthens with annealing, despite the absence of growth for these grains, through the continued nucleation of new grains.

Grain Growth in Nanocrystalline Nickel

1999 ◽  
Vol 580 ◽  
Author(s):  
G.D. Hibbard ◽  
U. Erb ◽  
K.T. Aust ◽  
G. Palumbo
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Grain Growth ◽  
Size Distributions ◽  
Nanocrystalline Nickel ◽  
Scanning Calorimetry ◽  
Solute Content ◽  
Grain Size Distributions ◽  
Thermal Stability Of ◽  
Total Solute Content

AbstractIn this study, the effect of grain size distribution on the thermal stability of electrodeposited nanocrystalline nickel was investigated by pre-annealing material such that a limited amount of abnormal grain growth was introduced. This work was done in an effort to understand the previously reported, unexpected effect, of increasing thermal stability with decreasing grain size seen in some nanocrystalline systems. Pre-annealing produced a range of grain size distributions in materials with relatively unchanged crystallographic texture and total solute content. Subsequent thermal analysis of the pre-annealed samples by differential scanning calorimetry showed that the activation energy of further grain growth was unchanged from the as-deposited nanocrystalline nickel.

scholarly journals Influence of grain growth on the thermal structure of protoplanetary discs

2020 ◽  
Vol 640 ◽  
pp. A63 ◽  
Author(s):  
Sofia Savvidou ◽  
Bertram Bitsch ◽  
Michiel Lambrechts
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Grain Growth ◽  
Thermal Structure ◽  
Size Composition ◽  
Size Distributions ◽  
Migration Rates ◽  
Grain Size Distributions ◽  
Hydrodynamical Simulations ◽  
Protoplanetary Discs

The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, for example, by considering only a single particle size. In the present work, we perform 2D hydrodynamical simulations of protoplanetary discs where the opacity is self-consistently calculated for the dust population, taking into account the particle size, composition, and abundance. We first compared simulations utilizing single grain sizes to two different multi-grain size distributions at different levels of turbulence strengths, parameterized through the α-viscosity, and different gas surface densities. Assuming a single dust size leads to inaccurate calculations of the thermal structure of discs, because the grain size dominating the opacity increases with orbital radius. Overall the two grain size distributions, one limited by fragmentation only and the other determined from a more complete fragmentation-coagulation equilibrium, give comparable results for the thermal structure. We find that both grain size distributions give less steep opacity gradients that result in less steep aspect ratio gradients, in comparison to discs with only micrometer-sized dust. Moreover, in the discs with a grain size distribution, the innermost (<5 AU) outward migration region is removed and planets embedded in such discs experience lower migration rates. We also investigated the dependency of the water iceline position on the alpha-viscosity (α), the initial gas surface density (Σg,0) at 1 AU and the dust-to-gas ratio (fDG) and find rice ∝ α0.61Σg,00.8fDG0.37 independently of the distribution used in the disc. The inclusion of the feedback loop between grain growth, opacities, and disc thermodynamics allows for more self-consistent simulations of accretion discs and planet formation.

Orientationally Resolved Grain Size Distributions in Thin Films

1998 ◽  
Vol 273-275 ◽  
pp. 237-242 ◽  
Author(s):  
J. Greiser ◽  
Peter Müllner ◽  
E. Arzt
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Size Distributions ◽  
Grain Size Distributions

Temporal Evolution of Grain Size Distributions in Two-Dimensional Pinned Cells

2004 ◽  
Vol 467-470 ◽  
pp. 1003-1008
Author(s):  
C.H. Wörner ◽  
A. Olguín
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Experimental Approach ◽  
Temporal Evolution ◽  
Size Distributions ◽  
Two Dimensional ◽  
Pinning Centers ◽  
Grain Size Distributions ◽  
Polycrystalline Aggregates

The distribution of sizes for grain growth in presence of pinning centers (Zener pinned growth) is communicated at different times. The experimental approach uses the well-known similitude between growth in polycrystalline aggregates and cellular soap froths. Two-dimensional results are communicated with grain growth limited by a set of randomly distributed rounded pins.

TEM Study of FePt and FePt:C/FePt Composite Double-Layered Thin Films

2013 ◽  
Vol 275-277 ◽  
pp. 1952-1955
Author(s):  
Ling Fang Jin ◽  
Xing Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Magnetic Properties ◽  
Composite Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

New functional nanocomposite FePt:C thin films with FePt underlayers were synthesized by noneptaxial growth. The effect of the FePt layer on the ordering, orientation and magnetic properties of the composite layer has been investigated by adjusting FePt underlayer thickness from 2 nm to 14 nm. Transmission electron microscopy (TEM), together with x-ray diffraction (XRD), has been used to check the growth of the double-layered films and to study the microstructure, including the grain size, shape, orientation and distribution. XRD scans reveal that the orientation of the films was dependent on FePt underlayer thickness. In this paper, the TEM studies of both single-layered nonepitaxially grown FePt and FePt:C composite L10 phase and double-layered deposition FePt:C/FePt are presented.

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.

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