The instability of polycrystalline thin films: Experiment and theory

1990 ◽  
Vol 5 (1) ◽  
pp. 151-160 ◽  
Author(s):  
K. T. Miller ◽  
F. F. Lange ◽  
D. B. Marshall
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Grain Growth ◽  
Spherical Surface ◽  
Polycrystalline Film ◽  
Yttrium Nitrate ◽  
Zirconium Acetate ◽  
Polycrystalline Thin Films ◽  
Average Grain Size

Dense polycrystalline thin films of ZrO2 (3 and 8 mol % Y2O3) were produced by the pyrolysis of zirconium acetate precursor films, which were deposited on single crystal Al2O3 substrates by spin-coating aqueous solutions of zirconium acetate and yttrium nitrate. Dense films were heat treated to encourage grain growth. With grain growth, these films broke into islands of ZrO2 grains. Identical areas were examined after each heat treatment to determine the mechanism that causes the polycrystalline film to uncover the substrate. Two mechanisms were detailed: (a) for a composition which inhibited grain growth and produced a polycrystalline film with very small grains, the smallest grains would disappear to uncover the substrate, and (b) for a composition which did not inhibit grain boundary motion, larger grains grew by enveloping a smaller grain and then developed more spherical surface morphologies, uncovering the substrate at three grain junctions. In both cases, the breakup phenomenon occurred when the average grain size was larger than the film thickness. Thermodynamic calculations show that this breakup lowers the free energy of the system when the grain-size-to-film-thickness ratio exceeds a critical value. These calculations also predict the conditions needed for polycrystalline thin film stability.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

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.

The Instability of Polycrystalline Thin Films: Experiment and Theory

1988 ◽  
Vol 121 ◽  
Author(s):  
K. T. Miller ◽  
F. F. Lange ◽  
D. B. Marshall
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Free Energy ◽  
Grain Growth ◽  
Spin Coating ◽  
Polycrystalline Thin Film ◽  
Film Stability ◽  
Zirconium Acetate ◽  
Polycrystalline Thin Films ◽  
Thin Film Stability

ABSTRACTDense polycrystalline thin films of ZrO2 (3 and 8 mol% Y2O3) were produced by the pyrolysis of zirconium acetate precursor films, which were deposited on single crystal Al2O3 substrates by spin-coating solutions of zirconium acetate. With grain growth, these films broke into islands of ZrO2 grains. Thermodynamic calculations show that this break up lowers the free energy of the system. These calculations also predict the conditions needed for polycrystalline thin film stability.

The yield stress of polycrystalline thin films

1993 ◽  
Vol 8 (2) ◽  
pp. 237-238 ◽  
Author(s):  
C.V. Thompson
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Yield Stress ◽  
Size Dependence ◽  
Detailed Understanding ◽  
Polycrystalline Thin Films ◽  
Observed Behavior

In recent experiments it has been shown that the yield stress of polycrystalline thin films depends separately on the film thickness and the grain size. It was also shown that the grain size dependence varies as the reciprocal of the grain size. In this paper an analysis is presented which leads to these results and provides a more detailed understanding of the origins of the observed behavior.

The Effect of Solute Drag on Grain Growth in Thin Films

1993 ◽  
Vol 317 ◽  
Author(s):  
H.J. Frost ◽  
Y. Hayashi ◽  
C.V. Thompson ◽  
D.T. Walton
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Driving Forces ◽  
Boundary Migration ◽  
Solute Drag ◽  
Polycrystalline Thin Films ◽  
Average Curvature ◽  
Grain Size Distributions ◽  
Dimensional Simulation

ABSTRACTWe have modelled the microstructural evolution of polycrystalline thin films during grain growth under the situation in which grain boundary migration becomes impeded by solute drag. For this we use a two-dimensional simulation of capillarity-driven grain growth in which grain boundaries migrate at velocities proportional to local curvature. At high driving forces, corresponding to high curvatures, the boundaries are given a mobility corresponding to drag-free motion. At low driving forces, corresponding to curvatures less than some critical value, the boundaries are given a lower mobility which models the effect of solute drag. During grain growth the average curvature of boundary segments decreases. When the boundary curvatures begin to fall below the critical curvature, the grain size distribution evolves to a lognormal distribution, which is maintained as significant further grain growth occurs. This is in accordance with many experimental grain size distributions which are commonly observed to be lognormal.

CRITICAL SURFACE TENSION, CRITICAL SURFACE ENERGY AND PARACHOR OF MnSO3 THIN FILM

2016 ◽  
Vol 23 (03) ◽  
pp. 1650009 ◽  
Author(s):  
İ. A. KARIPER
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Tension ◽  
Grain Size ◽  
Surface Energy ◽  
Film Thickness ◽  
Critical Surface ◽  
Critical Surface Tension ◽  
Average Grain Size ◽  
The Relationship

This study examines the critical surface energy of manganese sulfite (MnSO[Formula: see text] crystalline thin film, produced via chemical bath deposition (CBD) on substrates. In addition, parachor, which is an important parameter of chemical physics, and its relationship with grain size, film thickness, etc., has been investigated for thin films. For this purpose, MnSO3 thin films were deposited at room temperature using different deposition times. Structural properties of the films, such as film thickness and average grain size, were examined using X-ray diffraction; film thickness and surface properties were measured by and atomic force microscope; and critical surface tension of MnSO3 thin films was measured with Optical Tensiometer and calculated using Zisman method. The results showed that critical surface tension and parachor of the films have varied with average grain size and film thickness. Critical surface tension was calculated as 32.97, 24.55, 21.03 and 12.76[Formula: see text]mN/m for 14.66, 30.84, 37.07 and 44.56[Formula: see text]nm grain sizes, respectively. Film thickness and average grain size have been increased with the deposition time and they were found to be negatively correlated with surface tension and parachor. The relationship between film thickness and parachor was found as [Formula: see text] whereas the relationship between average grain size and parachor was found as [Formula: see text] We also showed the relationships between parachor and some thin films parameters.

Persistent current relaxation in polycrystalline superconducting thin films

2014 ◽  
Vol 28 (22) ◽  
pp. 1450152
Author(s):  
L. V. Belevtsov
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Relaxation Rate ◽  
Persistent Current ◽  
Superconducting Thin Films ◽  
Material Parameters ◽  
Polycrystalline Thin Films ◽  
Current Relaxation

The relaxation rate of persistent current is studied theoretically in superconducting polycrystalline thin films. It is shown that varying the material parameters of grain anisotropy, grain size and film thickness does guide to a change of the current relaxation rate (CRR) mode. The point of degeneracy of CRR was obtained. The film-thickness dependent maxima are found in the behavior of CRR.

Effect of Annealing Conditions on the Grain Size of Nanocrystalline Copper Thin Films

2008 ◽  
Vol 587-588 ◽  
pp. 483-487 ◽  
Author(s):  
Sonia Simões ◽  
Rosa Calinas ◽  
P.J. Ferreira ◽  
M. Teresa Vieira ◽  
Filomena Viana ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Grain Size ◽  
Grain Growth ◽  
Copper Substrate ◽  
Nanocrystalline Metals ◽  
Nanocrystalline Copper ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Average Grain Size

Nanocrystalline metals demonstrate a broad range of fascinating mechanical properties at the nanoscale, namely a significant increase in hardness and superior yield stress. In this regard, understanding grain growth in nanocrystalline metals is crucial, particularly because nano size grains are characterized by a high curvature, which results in a high driving force for grain growth. In this work, the effect of annealing conditions on grain size of copper nanocrystalline thin films was investigated. The nanocrystalline copper thin films were first deposited by d.c. magnetron sputtering on a copper substrate. The specimens were then annealed in vacuum at 100, 300 and 500°C from 10 minutes to 5 hours. Transmission electron microscopy observations revealed that the as-deposited thin films have a bimodal grain size distribution; an average grain size of 43±2nm and the presence of nanotwins. Abnormal grain growth was observed for some samples annealed. Increasing the annealing time induced significant grain growth and promoted twin formation in the larger grains. Finally, the hardness of these nanocrystalline Cu thin films was determined using atomic force microscope. The relation between mechanical properties, annealing conditions and grain size was analyzed.

scholarly journals On the multiplying factor for the estimation of the average grain size in thin films

2021 ◽  
Vol 196 ◽  
pp. 113748
Author(s):  
Srinivas K. Yadavalli ◽  
Mingyu Hu ◽  
Nitin P. Padture
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Average Grain Size

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

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