Slip of shuffle screw dislocations through tilt grain boundaries in silicon

Thumbnail Image
Date
2019-02-01
Authors
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Xiong, Liming
Associate Professor
Person
Research Projects
Organizational Units
Organizational Unit
Aerospace Engineering

The Department of Aerospace Engineering seeks to instruct the design, analysis, testing, and operation of vehicles which operate in air, water, or space, including studies of aerodynamics, structure mechanics, propulsion, and the like.

History
The Department of Aerospace Engineering was organized as the Department of Aeronautical Engineering in 1942. Its name was changed to the Department of Aerospace Engineering in 1961. In 1990, the department absorbed the Department of Engineering Science and Mechanics and became the Department of Aerospace Engineering and Engineering Mechanics. In 2003 the name was changed back to the Department of Aerospace Engineering.

Dates of Existence
1942-present

Historical Names

  • Department of Aerospace Engineering and Engineering Mechanics (1990-2003)

Related Units

Organizational Unit
Ames National Laboratory

Ames National Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, Iowa.

For more than 70 years, the Ames National Laboratory has successfully partnered with Iowa State University, and is unique among the 17 DOE laboratories in that it is physically located on the campus of a major research university. Many of the scientists and administrators at the Laboratory also hold faculty positions at the University and the Laboratory has access to both undergraduate and graduate student talent.

Organizational Unit
Mechanical Engineering
The Department of Mechanical Engineering at Iowa State University is where innovation thrives and the impossible is made possible. This is where your passion for problem-solving and hands-on learning can make a real difference in our world. Whether you’re helping improve the environment, creating safer automobiles, or advancing medical technologies, and athletic performance, the Department of Mechanical Engineering gives you the tools and talent to blaze your own trail to an amazing career.
Organizational Unit
Materials Science and Engineering

The Department of Materials Science and Engineering teaches the composition, microstructure, and processing of materials as well as their properties, uses, and performance. These fields of research utilize technologies in metals, ceramics, polymers, composites, and electronic materials.

History
The Department of Materials Science and Engineering was formed in 1975 from the merger of the Department of Ceramics Engineering and the Department of Metallurgical Engineering.

Dates of Existence
1975-present

Related Units

Journal Issue
Is Version Of
Versions
Series
Abstract

In this paper, molecular dynamics (MD) simulations of the interaction between tilt grain boundaries (GBs) and a shuffle screw dislocation in silicon are performed. Results show that dislocations transmit into the neighboring grain for all GBs in silicon. For Σ3, Σ9 and Σ19 GBs, when a dislocation interacts with a heptagon site, it transmits the GB directly. In contrast, when interacting with a pentagon site, it first cross slips to a plane on the heptagon site and then transmits the GB. The energy barrier is also quantified using the climbing image nudged elastic band (CINEB) method. Results show that Σ3 GB provides a barrier for dislocation at the same level of the Peierls barrier. For both Σ9 and Σ19 GBs, the barrier from the heptagon sites is much larger than the pentagon sites. Since the energy barrier for crossing all the GBs at the heptagon sites is only slightly larger than the Peierls barrier, perfect screw dislocations cannot pile up against these GBs. Furthermore, the critical shear stress averaged over the whole sample for the transmission through the Σ9 and Σ19 GBs is almost twice on heptagon site for initially equilibrium dislocation comparing with dislocations moving at a constant velocity.

Comments

This is a manuscript of an article published as Chen, Hao, Valery Levitas, and Liming Xiong. "Slip of shuffle screw dislocations through tilt grain boundaries in silicon." Computational Materials Science 157 (2019): 132-135. DOI: 10.1016/j.commatsci.2018.10.024. Posted with permission.

Description
Keywords
Citation
DOI
Copyright
Mon Jan 01 00:00:00 UTC 2018
Collections