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Structure of Materials, Part 3: Liquid Crystals, Defects, and Diffusion

Discover the structure of the materials that make up our modern world and learn how this underlying structure influences the properties and performance of these materials.
Structure of Materials, Part 3: Liquid Crystals, Defects, and Diffusion
This course is archived
Estimated 6 weeks
6–8 hours per week
Instructor-led on a course schedule
Optional upgrade available

About this course

Skip About this course
Structure determines so much about a material:  its properties, its potential applications, and its performance within those applications.  This course is the finale in a three-part series from MIT’s Department of Materials Science and Engineering that explores the structure of a wide variety of materials with current-day engineering applications.  Taken together, these three courses provide similar content to MIT’s sophomore-level materials structure curriculum.

Part 3 begins with an exploration of quasi-, plastic, and liquid crystals.  Next, we will learn how properties of materials are influenced and can be modified by structural defects. We will show that point defects are present in all crystals at finite temperatures and how their presence governs diffusion in materials. Next, we will explore dislocations in materials.  We will introduce the descriptors that are used to describe dislocations, we will learn about dislocation motion and consider how dislocations dramatically affect the strength of materials.  Finally, we will explore how defects can be used to strengthen materials, and we will learn about the properties of other structural defects such as stacking faults and grain boundaries.

At a glance

  • Language: English
  • Video Transcript: English

What you'll learn

Skip What you'll learn
  • The properties of liquid crystals and how these materials are used in modern display technologies
  • The presence of defects in all crystals at equilibrium
  • How defects impact numerous properties of materials—from the conductivity of semiconductors to the strength of structural materials
Part 1: Quasi, Plastic, and Liquid Crystals
  • Quasi crystals
  • An introduction to plastic and liquid crystals
  • Liquid crystal descriptors
  • Liquid crystal applications
Part 2: Introduction to Point Defects
  • Thermodynamics of point defects
  • Vacancies, interstitials, solid solutions and nonequilibrium defects
Part 3: Ionic Point Defects & Diffusion
  • Kröger-Vink notation
  • Extrinsic defects
  • Diffusion
Part 4: Dislocations and Deformation
  • Introduction to dislocations
  • Elastic and plastic deformation
  • Stress and strain
  • Dislocation descriptors
  • The Burgers vector
  • Dislocation motion
  • Resolved shear stress
Part 5: Strengthening & Surface Energy
  • Strengthening Mechanisms
  • Surface free energy
  • Wulff shape
Part 6: 2-Dimensional Defects
  • Surface defects
  • Stacking faults
  • Grain boundaries
  • Surface reconstruction
  • Linear defects in liquid crystals

About the instructors

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