chemistry/materials science and engineering c150alchemy.cchem.berkeley.edu/inorganic/class slides...

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, 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

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


arranged in a cube.


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･･･


arranged in anticuboctahedron


Examples: He, Be, Mg, Tl, Zn, La, OS

Stacking sequence = ･･･ABCABCABC･･･


arranged in cuboctahedron


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


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



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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