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• TA Office Hours: TBA (likely Tuesdays)• Required Text: “Understanding Solids” R. Tilley• Recommended Text: “Intro to Mat Sci for Engineers” Shackelford• Reserved Texts: SFL
– “The Principles of Engineering Materials,” Barrett, Nix & Tetelman
– “Phase Transformations in Metals and Alloys,” Porter & Easterling
• Introduction to Materials Science– Chemistry + Processing Structure Properties
• Structure– Review: Structure of the Atom & Chemical Bonding– Crystalline Structure– Structural Characterization (X-ray diffraction)– Amorphous Structure– Microstructure
• Defects in Crystalline Solids, Connections to Properties– Point Defects (0-D) and Diffusion & Ionic Conductivity– Dislocations (1-D) and Mechanical Deformation– Surfaces and interfaces (2-D)– Volume Defects (3-D) and Fracture
Course Content
• Electrons in Solids– Chemical Bonding, Revisited– Band Structure– Electronic Conductivity: Metals vs. Insulators
• Homework: weekly 50%– Assigned Wednesdays– Due following Wednesday, 5pm– Place in TA mailbox, 3rd floor Steele
• Midterm HW: Oct 26 - Nov 1 15%– Solo homework
• Final: Dec 7 - 09 35% – Take home
HW Collaboration Policy• Students are encouraged to discuss and work on
problems together. – During discussion, you may make/take notes
– However, do not bring and/or exchange written solutions or attempted solutions you generated prior to the discussion.
– If you’ve worked the problem out and you plan to help a friend, you should know the solution cold.
• Do not consult old problem sets, exams or their solutions.
• Solutions will be handed out on Friday, or possibly Monday. Assignments turned in late, but before solutions are available, will receive 2/3 credit. Assignments will not be accepted after solutions are handed out.
Midterm Homework• In lieu of a midterm exam there will be homework to be
performed on an individual basis. This homework must be completed without collaborative discussion.
• The problem set will focus primarily on recent lectures, but material from early topics may also be included.
• Similar to other homeworks, you will have one week to complete the assignment.
• You are permitted to utilize all available resources, with the exception of previous solutions, including ones from earlier in the year.
Structure of the Atom• “Electron in a box” – use quantum mechanics to solve
electron wave functions– Electron quantum numbers, orbitals– Electrical properties
• Qualitative description of chemical bonding– Electrons ‘orbit’ atomic nucleus
K
ML
Q.N.
n K, L, M “shell” n = 1, 2, 3 radius
l s, p, d “orbital” l = 0, 1 …. n-1
m px, py, pz “orientation” m = -l, -l + 1, …0,...l - 1, l
s spin s = ± ½
K-shell: n = 1 l = 0
1
32
1s m = 0 s = ± ½
L-shell: n = 2 l = {0, 1} 2s, 2p
m = 0 m = {-1, 0, 1} px. py. pz
Chemical notation
Structure of the Atom
• Electrons occupy these orbitals
• Pauling exclusion principle– Only one electron with a given set of QNs– For a multi-electron atom, fill up orbitals
beginning with lowest energy & go up
• Order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s,..
Chemical Bonding
• Atoms Molecules Solids
• Bonds form so as to produce filled outer shells
• Some atoms are a few electrons short– Electronegative: readily pick up a few electrons from other
atoms, become negatively charged
• Some atoms have a few electrons too many– Electropositive: readily give up a few electrons to other atoms,
how can carbon atoms fill px, py and pz orbitals if the other element is also electronegative?
Hybridized Bonds
one s + three p orbitals 4 (x 2) electron states(resulting orbital is a combination)
sp3 hybridization
diamond
also methane: CH4
• Elemental carbon (no other elements)
Chemical Bonding• Covalent – between electronegative elements• Metallic – between electropositive elements• Ionic – between different elements with differing