材料结构 2：结晶态

你将学到什么

课程概况

Structure determines so much about a material:  its properties, its potential applications, and its performance within those applications.  This course is the second 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 2 provides an introduction to the study of crystallography.  We begin by looking at crystals and their symmetries in two dimensions.  Then, we expand into three dimensions, exploring the underlying crystalline structures that underpin most of the materials that surround us.  Finally, we look at how tensors can be used to represent the properties of three-dimensional materials, and we show how these change as a function of the crystalline symmetry.

If you would like to explore the structure of materials further, we encourage you to enroll in Part 1 and Part 3 of the course.

Crystal structure image by User: Materialscientist on Wikimedia.
Photo of quartz by User: JJ Harrison on Wikimedia. (CC BY-SA) 2.5

课程大纲

Part 1: Symmetry in 2D Crystals

Translation, mirror, glide and rotation symmetry

Part 2: Point groups in 2D

Allowed rotational symmetries in crystals
The 10 2D point groups
An introduction to crystallographic notation

Part 3: Plane groups in 2D

The five 2D lattice types
The 17 plane groups in 2D

Part 4: Symmetry in 3D Crystals

Inversion, Roto-Inversion, and Roto-reflection
Screw symmetry

Part 5: 3D Space Point groups

Space point groups
Stereographic projection

Part 6: 3D Space Groups

Crystal lattices
Space groups

Part 7: An Introduction to Tensors

Symmetry constraints on materials properties
Coordinate transformation

预备知识

University-level chemistry
Part 1 of the course