crystal, glass, amorphous solid, ordered solid, long-range order, Bravais lattice, crystal system, point group, translation, rotation, symmetry plane, degree of symmetry, crystal basis, unit cell, face-centered cubic, simple cubic, body-centered cubic, hexagonal close-packed, rock salt structure, diamond cubic, birefringence, crystallography, nearest neighbor, Auguste Bravais, René Haüy, Robert Hooke, Christiaan Huygens, Nicolaus Steno
silicon (Si), boron (B), diamond (C)
glass, obsidian, quartz, calcite, tin (Sn), basalt, beryl, fluorite, gold (Au), aluminum (Al), copper (Cu), platinum (Pt), methane ice (CH4), rock salt (NaCl)
transistors, diodes, current rectification
cannonball stacking, tiling of 2D surfaces, fiber optics coupling, optical beam-splitter, colored gold
Before starting this session, you should be familiar with:
This session introduces the cubic unit cells, a key framework for discussing atomic-level processes in solids throughout this module and in later topics, such as Diffusion (Session 24) and Solid Solutions (Session 33 onwards). The next module on Amorphous Solids (Session 21 onwards) discusses non-crystalline materials in more detail, contrasting their structure and properties with the ordered solids studied here.
After completing this session, you should be able to:
Continuing last lecture’s explanation of extrinsic semiconductors, the Electronic Materials module ends at 13:00 with an exploration of p-type doping and an overview of the p-n junction. Prof. Sadoway moves on to introduce a classification for materials based on the degree of atomic-level order, contrasting ordered solids (crystals, e.g. quartz, calcite) with amorphous solids (glasses, e.g. obsidian). The 7 crystal systems and 14 Bravais lattices are introduced:
Crystal structures are described using a basis, which may be an atom, a group of ions (e.g. rock salt (NaCl)), or a molecule (e.g. methane (CH4(s)), proteins), repeated at the points of a Bravais lattice. Since they apply to many common metals and minerals, this course focuses on the cubic crystal systems: simple, body-centered, and face-centered.
Chapman, Allan. England’s Leonardo: Robert Hooke and the Seventeenth-Century Scientific Revolution. Philadelphia, PA: Institute of Physics Publishing, 2005. ISBN: 9780750309875.
Steno, Nicolaus. The Prodromus of Nicolaus Steno’s Dissertation Concerning a Solid Body Enclosed by Process of Nature within a Solid. Translated by John Garrett Winter. New York, NY: Macmillan, 1916.
Cutler, Alan. The Seashell on the Mountaintop: A Story of Science, Sainthood, and the Humble Genius Who Discovered a New History of the Earth. New York, NY: Plume, 2004. ISBN: 9780452285460.
Dijksterhuis, Fokko Jan. Lenses and Waves: Christiaan Huygens and the Mathematical Science of Optics in the Seventeenth Century. Boston, MA: Kluwer, 2004. ISBN: 9789048167067.
Vallier, Dora. Braque: The Complete Graphics: Catalogue Raisonne. New York, NY: Alpine Fine Arts Collection, 1988. ISBN: 9780881680065.
Talking Heads. “Burning Down the House.” Speaking in Tongues. Sire Records, 1983.