The Geometry of Grain Disappearance in Thin Polycrystalline Films

1994 ◽  
Vol 343 ◽  
Author(s):  
S. J. Townsend ◽  
C. S. Nichols
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Polycrystalline Films ◽  
Surface Drag ◽  
Columnar Grains ◽  
Simulation Results ◽  
Thin Polycrystalline

ABSTRACTDuring grain growth, shrinking columnar grains in thin-film polycrystalline microstructures eventually reach sizes comparable to the film thickness. Due to surface drag, the sides of such grains may bow inward rather than remaining fiat through the bulk of the film. The grain boundaries delimiting such small shrinking grains may become unstable long before the surface of the shrinking grain reaches zero area. We report simulation results demonstrating such an instability in the limit of infinite surface drag. This may lead to extremely rapid disappearance of 4- or 5- sided grains, such as have been recently observed in in situ hot-stage TEM experiments on aluminum thin film polycrystals.

Substrates with Programmable Heater Arrays for In-Situ Observation of Microstructural Evolution of Polycrystalline Films: Towards Real Time Control of Grain Growth

MRS Advances ◽  
2016 ◽  
Vol 1 (26) ◽  
pp. 1947-1952 ◽  
Author(s):  
Prabhu Balasubramanian ◽  
Chengjian Zheng ◽  
Yixuan Tan ◽  
Genevieve Kane ◽  
Antoinette Maniatty ◽  
...  
Keyword(s):  
Grain Growth ◽  
Microstructural Evolution ◽  
Control Strategies ◽  
Experimental Simulation ◽  
In Situ Observation ◽  
Temperature Profiles ◽  
Theory Approach ◽  
Polycrystalline Films ◽  
Real Time Control

ABSTRACTAn integrated experimental – simulation – control theory approach designed to enable adaptive control of microstructural evolution in polycrystalline metals is described. A micro-heater array, containing ten addressable channels, is used to create desired temperature profiles across thin polycrystalline films in situ to a scanning electron microscope (SEM). The goal is that on heating with controlled temperature profiles, the evolution of grain growth within the film can be continuously monitored and compared to Monte Carlo simulations of trajectories towards a desired microstructure. Feed-forward and feedback control strategies are then used to guide the microstructure along the desired trajectory.

scholarly journals Stacking fault reduction during annealing in Cu-poor CuInSe2 thin film solar cell absorbers analyzed by in situ XRD and grain growth modeling

2019 ◽  
Vol 125 (3) ◽  
pp. 035303 ◽  
Author(s):  
Helena Stange ◽  
Stephan Brunken ◽  
Dieter Greiner ◽  
Marc Daniel Heinemann ◽  
Daniel Antonio Barragan Yani ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Grain Growth ◽  
Thin Film Solar Cell ◽  
Growth Modeling ◽  
Stacking Fault ◽  
In Situ Xrd ◽  
Cuinse2 Thin Film

scholarly journals Deposition of Al Thin Film on Steel Substrate: The Role of Thickness on Crystallization and Grain Growth

Metals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 12 ◽  
Author(s):  
Hayk Khachatryan ◽  
Sung-Nam Lee ◽  
Kyoung-Bo Kim ◽  
Moojin Kim
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Film Thickness ◽  
Grain Growth ◽  
Growth Process ◽  
Film Growth ◽  
Specular Reflection ◽  
Steel Substrate ◽  
Al Thin Film

In this study, we deposited aluminum (Al) films of different thicknesses on steel substrate and examined their phase, microstructure, and film growth process. We estimated that films of up to 30 nm thickness were mainly amorphous in nature. When the film thickness exceeded 30 nm, crystallization was observed. The further increase in film thickness triggered grain growth, and the formation of grains up to 40 nm occurred. In such cases, the Al film had a cross-grained structure with well-developed primary grains networks that were filled with small secondary grains. We demonstrated that the microstructure played a key role in optical properties. The films below 30 nm showed higher specular reflection, whereas thicker films showed higher diffuse reflections.

Lubricant Flow and Evaporation Model for Heat Assisted Magnetic Recording Systems Including Reactive End-Group Effects and Thin-Film Viscosity

2012 ◽  
Author(s):  
Joanna E. Bechtel ◽  
David B. Bogy
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Magnetic Recording ◽  
Disjoining Pressure ◽  
Thickness Dependence ◽  
Heat Assisted Magnetic Recording ◽  
Lubricant Flow ◽  
Simulation Results ◽  
Thin Film Viscosity ◽  
Film Viscosity

The lubricant applied to the disk in a hard drive is a critical component for head-disk interface reliability. In Heat Assisted Magnetic Recording (HAMR), the heat supplied to the disk by the laser will add new thermal considerations to lubricant performance. Investigations into how the lubricant behaves at the small time and length scales seen in HAMR systems need to be conducted numerically. Published works on HAMR lubricant modeling have considered only the van der Waals contribution to disjoining pressure, commonly called the dispersive component, and do not consider the film thickness dependence of viscosity. However, lubricants with reactive end groups such as Fomblin Zdol are widely used, and such simple disjoining pressure and viscosity models do not capture certain lubricant behavior. We have developed a simulation tool that incorporates film thickness dependencies of viscosity and polar and dispersive disjoining pressure into a continuum lubrication model. We investigate the effect of initial thickness on lubricant flow and evaporation under HAMR write conditions considering both components of disjoining pressure and thin-film viscosity. Simulation results indicate the effect of including polar disjoining pressure depends on the initial lubricant thickness. The inclusion of viscosity thickness dependence does not affect simulation results under scanning laser conditions but will be important in reflow simulations.

Grain Boundary Responses to Local and Applied Stress: An In Situ TEM Deformation Study

2006 ◽  
Vol 976 ◽  
Author(s):  
Bryan Miller ◽  
Jamey Fenske ◽  
Dong Su ◽  
Chung-Ming Li ◽  
Lisa Dougherty ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Transmission Electron Microscope ◽  
In Situ Tem ◽  
Deformation Twins ◽  
Transmission Electron ◽  
Dislocation Interactions

AbstractDeformation experiments at temperatures between 300 and 750 K have been performed in situ in the transmission electron microscope to investigate dislocation interactions and reactions with grain boundaries and other obstacles. Dislocations, both partial and perfect, as well as deformation twins have been observed being emitted from grain boundaries and, in some cases, even the same grain boundary. The ejection of dislocations from the grain boundary can result in its partial or total annihilation. In the latter case, the disintegration of the grain boundary was accompanied by grain growth and a change in misorientation.

Atomistic Simulations of Dislocation-Loop Glidings in Al(111) Nanoindentation

2004 ◽  
Vol 261-263 ◽  
pp. 735-740
Author(s):  
Sukky Jun ◽  
Young Min Lee ◽  
Sung Youb Kim ◽  
Se Young Im
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Film Thickness ◽  
Dislocation Loop ◽  
Dislocation Motion ◽  
Dynamics Simulation ◽  
Atomistic Simulations ◽  
Dislocation Loops ◽  
Simulation Results ◽  
Film Nucleation

Molecular dynamics simulation of nanoindentation on Al(111) surface is presented. The simulation is performed using the Ercolessi-Adams glue potential and the Berendsen thermostat. Boundary conditions of 'pseudo' thin film are imposed in order to focus on the dislocation motion in ultra-thin film. Nucleation and development of defects underneath the indenter tip are visualized, and the gliding patterns of dislocation loops are investigated with particular emphasis on the effect of film thickness. Simulation results show that the early emission of dislocation loop is highly dependent on the film thickness.

Densification and grain growth of Al-doped ZnO

2001 ◽  
Vol 16 (2) ◽  
pp. 459-468 ◽  
Author(s):  
Jiaping Han ◽  
P. Q. Mantas ◽  
A. M. R. Senos
Keyword(s):  
Electron Microscopy ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Spinel Phase ◽  
Growth Exponent ◽  
Second Phase ◽  
Surface Drag ◽  
Transmission Electron ◽  
Growth Activation ◽  
Doped Zno

The densification and grain growth of ZnO doped with Al from 0.08 to 1.2 mol% were investigated during isothermal sintering between 1100 and 1400 °C. The Al dopant significantly inhibited the grain growth of ZnO and increased the grain growth exponent from 3 for pure ZnO to 4–6 for Al-doped ZnO. The grain growth activation energy was also changed from approximately 200 kJ/mol for pure ZnO to approximately 480 kJ/mol for Al-doped ZnO. The results of x-ray diffraction, scanning electron microscopy, and transmission electron microscopy showed that a ZnAl2O4 spinel phase existed as a second phase at the ZnO grain boundaries in Al-doped ZnO specimens. The spinel particles exerted an effective drag (pinning) on the migration of ZnO grain boundaries. The analyses of the Al doping effect on the densification rate provided evidence that the driving force for densification was reduced by the second-phase particles. A mechanism of pore surface drag (pinning) on densification equivalent to the observed drag (pinning) of grain boundaries on grain growth was proposed.

Characterization of Thin Film Dissolution in Water with in Situ Monitoring of Film Thickness Using Reflectometry

2016 ◽  
Vol 8 (27) ◽  
pp. 17622-17630 ◽  
Author(s):  
Alexander S. Yersak ◽  
Ryan J. Lewis ◽  
Jenny Tran ◽  
Yung C. Lee
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
In Situ Monitoring
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