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Chemistry/Materials Science and Engineering C150
Introduction to Materials Chemistry
Class will meet Tuesdays and Thursdays, 8:00-9:30 am, in 433 Latimer Hall.
Instructor: Jeffrey Long (211 Lewis Hall)
Office Hours: Fridays 3-4 pm or by appointment
Teaching Assistant: Khetpakorn (Job) Chakarawet
Office Hours: Tuesdays and Wednesdays, 2-3 pm (209 Lewis Hall)
Description: This course is primarily intended for undergraduate students. The application of basic chemical principles to problems in materials discovery, design, and characterization will be discussed. Topics covered will include inorganic solids, nanoscale materials, polymers, and biological materials, with specific focus on the ways in which atomic-level interactions dictate the bulk properties of matter. Each student will also choose a more specialized topic on which to give a presentation and write a final paper.
Prerequisite: Chemistry 104A
Course Web Site: http://alchemy.cchem.berkeley.edu/inorganic/
Grading: Problem Sets (4) 10%
Exam 1 25%
Exam 2 25%
Special Topics Presentation 15%
Final Paper 25%
Recommended Texts
Burdett, Chemical Bonding in Solids, Oxford University Press, 1995.
Fahlman, Materials Chemistry, Springer, 2007.
Other Texts
Bhat, Biomaterials, 2nd Ed., Alpha Science, 2002.
Carraher, Introduction to Polymer Chemistry, CRC Press, 2006.
Cox, The Electronic Structure and Chemistry of Solids, Oxford University Press, 1995.
Flory, Principles of Polymer Chemistry, Cornell University Press, 1953.
Gersten and Smith, The Physics and Chemistry of Materials, John Wiley & Sons, 2001.
Hiemenz and Lodge, Polymer Chemistry, 2nd Ed., CRC Press, 2007.
Hoffmann, Solids and Surfaces: A Chemist’s View of Bonding in Extended Structures, VCH, 1988.
Lalena and Cleary, Principles of Inorganic Materials Design, John Wiley & Sons, 2005.
Ozin and Arsenault, Nanochemistry: A Chemical Approach to Nanomaterials, RSC Pub., 2005.
Spaldin, Magnetic Materials, Cambridge University Press, 2003.
Sutton, Electronic Structure of Materials, Oxford University Press, 1994.
Tilley, Understanding Solids, John Wiley & Sons, 2004.
Young and Lovell, Introduction to Polymers, 2nd Ed., Academic Press, 2000.
Course Schedule
Class will meet on Tuesdays and Thursdays from 8:00-9:30 am in 433 Latimer Hall. Exams 1 and 2 will be given in class.
Tuesday, 1/16 Introduction and Review of Simple Solid Structures
Thursday, 1/18 Synthetic Methods
Tuesday, 1/23 Electronic Materials I
Thursday, 1/25 no class
Tuesday, 1/30 Electronic Materials II
Thursday, 2/1 Electronic Materials III
Tuesday, 2/6 Electronic Materials IV Problem Set 1 due
Thursday, 2/8 Magnetic Materials I
Tuesday, 2/13 Magnetic Materials II
Thursday, 2/15 Magnetic Materials III Problem Set 2 due
Tuesday, 2/20 Exam 1
Thursday, 2/22 Optical Materials I
Tuesday, 2/27 Optical Materials II
Thursday, 3/1 Optical Materials III
Tuesday, 3/6 Nanoscale Materials I
Thursday, 3/8 Nanoscale Materials II
Tuesday, 3/13 Porous Solids Problem Set 3 due
Thursday, 3/15 Polymers I
Tuesday, 3/20 Polymers II
Thursday, 3/22 Polymers III
Tuesday, 3/27 Spring Recess (no class)
Thursday, 3/29 Spring Recess (no class)
Tuesday, 4/3 Biomaterials Problem Set 4 due
Thursday, 4/5 Exam 2
Tuesday, 4/10 Special Topics Presentations
Thursday, 4/12 Special Topics Presentations
Tuesday, 4/17 Special Topics Presentations
Thursday, 4/19 Special Topics Presentations
Tuesday, 4/24 Special Topics Presentations
Thursday, 4/26 Special Topics Presentations
Tuesday, 5/1 RRR Week (no class)
Thursday, 5/3 RRR Week (no class)
Friday, 5/4 Final Paper Due (5 pm)
Course Schedule
Why Study Solids?
1. ALL compounds are solids under certain conditions. Many exist only as solids.
2. Solids are of immense technological importanceA. Appearance
• Precious and semi-precious gemstones
B. Mechanical Properties• Metals and alloys (e.g. titanium for aircraft)
• Cement concrete (Ca3SiO5)
• Ceramics (e.g. clays, BN, SiC)
• Lubricants (e.g. graphite, MoS2)
• Abrasives (e.g. diamond, quartz (SiO2), corundum (SiC))
C. Electronic properties• Metallic conductors (e.g. Cu, Ag, Au)
• Semiconductors (e.g. Si, GaAs)
• Superconductors (e.g. Nb3Sn, YBa2Cu3O7-x)
• Electrolytes (e.g. LiI in pacemaker batteries)
• Piezoelectrics (e.g. α–quartz (SiO2) in watches)
D. Magnetic Properties• e.g. CrO2, Fe3O4 for recording technology
E. Optical Properties• Pigments (e.g. TiO2 in white paints)
• Phosphors (e.g. Eu3+ in Y2O3 is red in TVs)
• Lasers (e.g. Cr3+ in Al2O3 is ruby)
• Nonlinear optics (e.g. frequency-doubling with KTiOPO4)
Why Study Solids?
Crystal Structures: Crystal Symmetry
The following elements from molecular symmetry are consistent with three-dimensional crystal symmetry:
E, C2, C3, C4, C6, S3, S6, i, σ
All crystals possess three additional symmetry elements, each corresponding to a translation vector:
a, b, c
The collection of symmetry elements present in a specific crystal is called its space group. There are 230 different space groups.
Example: cyanuric triazide (C3h)
Five-fold rotational symmetry is incompatible with translation symmetry
Proof:
1. Start at a point x situated on a C5 axis
2. Assume that translational symmetry
exists
3. If this is so, then we can choose a
shortest translation vector a such that it
ends on point y with a surrounding
identical to x in arrangement and
orientation
4. Perform C5 operations to generate
environment of point x
5. Point y must have an identical
environment (dashed lines). This
includes point z, which, by symmetry,
must also have a surrounding identical
to x in arrangement and orientation.
6. The line xz forms a vector shorter than a
7. Statement 3 is violated, and translational
symmetry cannot exist
xa y
z
= C5 perpendicular to page
The translational symmetry elements in a crystal
define a periodic array of points called the Bravais
lattice:
{n1a + n2b + n3c} for n1, n2, n3 integers
Every points in a Bravais lattice is equivalent.
Example:
simple cubic lattice
(0, 0, 0)
(4, 2, 3)
The symmetry of a crystal with respect to its Bravais
lattice allows it to be classified as belonging to one of
seven different crystal systems:
crystal system minimal symmetry
cubic 4C3 along body-diagonals of cube
hexagonal C6 parallel to c
rhombohedral C3 parallel to a + b + c
tetragonal C4 parallel to c
orthorhombic 3C2 parallel to a, b, and c
monoclinic C2 parallel to b
triclinic E
A unit cell of a crystal is the parallelpipedic volume defined
by a, b, and c, which, upon translation, generates the entire
crystal.
Thus, the unit cell depends on the choices of vectors a, b,
and c. The following are unit cells of the simple cubic lattice.
A primitive unit cell contains no lattice points other than those
located at its corners.
simple cubic lattice unit cells
The 14 Bravais LatticesConventional Unit Cells Arranged by Crystal System
The 14 Bravais LatticesConventional Unit Cells Arranged by Crystal System
16
Packing of Spheres
Simple Cubic (SC)
Body-centered Cubic (BCC)
Each sphere has 6 nearest neighbors
arranged in an octahedron.
Space filled = 52.36%
Example: Po
Each sphere has 8 nearest neighbors
arranged in a cube.
Space filled = 68.02%
Examples: Na, Fe, Mo, Tl
Closest Packing
First Layer
Hexagonal
close-packed
(hcp) site
Cubic close-
packed (ccp)
site
There are two types of sites to position the third layer on:
Closest Packing
Second Layer
A
C
B
Closest Packing
Third Layer for CCP
Cubic Closest Packing (CCP) = Face-Centered Cubic (FCC)
A
A
B
Closest Packing
Third Layer for HCP
Hexagonal Closest Packing (HCP)
Comparison of Closest Packed Structures
Stacking sequence = ・・・ABABAB・・・
Each sphere has 12 nearest neighbors
arranged in anticuboctahedron
Space filled = 74.05%
Examples: He, Be, Mg, Tl, Zn, La, OS
Stacking sequence = ・・・ABCABCABC・・・
Each sphere has 12 nearest neighbors
arranged in cuboctahedron
Space filled = 74.05%
Examples: Al, Ca, Ni, Cu, Xe, Pb
A
AB
A
CB
Holes in Lattices
Tetrahedral hole in
cleft between four
spheres
Octahedral hole in
cleft between six
spheres
tetrahedral
hole
octahedral
hole
1. MX
• Cesium chloride: CsCl, CaS, TiCl, CsCN; CN(M, X) = 8
SC lattice of anions X, cubic holes filled with cations M
• Rock-salt: NaCl, LiCl, KBr, MgO, AgCl, TiO, NiO, ScN; CN(M, X) = 6
FCC lattice of anions X in which cations M occupy octahedral holes
• Nickel arsenide: NiAs, NiS, FeS, CoS, CoTe
HCP lattice of anions X, octahedral holes filled with M, X atoms
surrounded in trigonal prismatic arrangement of M
CN(Ni, As) = 6
2 NiAs/unit cell
As: 2(1) = 2
Ni: 2(1/3) + 2(1/6) +
4(1/6) + 4(1/12) = 2
Important Structure Types
• Sphalerite: ZnS, CuCl, CdS, HgS, GaP, InAs, CuFeS2
FCC lattice of anions X in which cations M occupy tetrahedral holes
• Wurtzite: ZnS, ZnO, BeO, AgI, AlN, SiC, InN, NH4F
HCP lattice of anions X in which cations M occupy tetrahedral holes
CN (Zn, S) = 4
CN (Zn, S) = 4
ZnS in the sphalerite and wurtzite lattices
are polymorphs
Important Structure Types
2. MX2, M2X
• Fluorite: CaF2, UO2, CeO2, BaCl2, HgF2, PbO2
FCC lattice of cations M in which anions X occupy tetrahedral holes; CsCl
structure in which one-half of the cations are absent
• Antifluorite: M2O (M = Li, Na, K, Rb); M2S, M2Se (M = Li, Na, K)
Inverse of the fluorite structure
CN (M) = 4, CN (X) = 8
CN (Ca) = 8
CN (F) = 4
Important Structure Types
Important Structure Types
3. ABX3
• Perovskite: CaTiO3, BaTiO3, SrTiO3, RbCaF3
Cubic lattice with B (or A) at unit cell corners, X on edges, and A (or B)
at center
CN (A) = 12
CN (B) = 6
Reference text for inorganic crystal structures:
Wells, Structural Inorganic Chemistry, 5th Ed., Oxford University Press, 1984.
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