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Some References:

Some References:

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Some References:

Colloids – A lot of what I presented is in -"Thermodynamics and Hydrodynamics of Hard Spheres; the role of gravity.", P. M. Chaikin, in Soft and Fragile Matter, Nonequilibrium Dynamics, Metastability and Flow, ed. By M. E. Cates and M. R. Evans, (Institute of Physics Publishing, London, 2000) and there are more general references and it is a good volume.

Some of our stuff:

Z. Cheng, W.B. Russel, and P.M. Chaikin "Controlled growth of

hard-sphere colloidal crystals", Nature 401, 893 - 895 (1999).

"Crystallization Kinetics of Hard Spheres in Microgravity in the Coexistence Regime: Interactions between Growing Crystallites", Zhengdong Cheng, P. M. Chaikin,

Jixiang Zhu, W. B. Russel, and W. V. Meyer, Phys. Rev. Lett. {\bf 88}, 015501 (2002).

"Colloidal hard-sphere crystallization kinetics in microgravity and normal gravity", ZD Cheng ,JX Zhu ,WB Russel ,WV Meyer ,PM Chaikin,APPLIED OPTICS {\bf 40}, 4146-4151 (2001).

"Phase diagram of hard spheres", Cheng Z, Chaikin PM, Russel WB, Meyer WV, Zhu J, Rogers RB, Ottewill RH, MATERIALS \& DESIGN,{\bf 22}, 529-534 (2001).

Phonons in an Entropic Crystal Zhengdong Cheng, Jixiang Zhu,

William B. Russel, P. M. Chaikin, Phys. Rev. Lett. 85, 1460 (2000)

Nature of the divergence in low shear viscosity of colloidal hard-sphere dispersions, Cheng ZD, Zhu JX, Chaikin PM, Phan SE, Russel WB, PHYSICAL REVIEW E65 (4): art. no. 041405 Part 1 APR 2002

Good diblock references:

F. S. Bates, and G. H. Fredickson, Physics Today Feb, 1999

F. S. Bates, Science, 251, 898

Some of our stuff is in:

C. Harrison, D.H. Adamson, Z. Cheng, J.M. Sebastian, S.

Sethuraman, D.A. Huse, R.A. Register, and P.M. Chaikin,

"Mechanisms of Ordering in Striped Patterns", Science, 290,

1558-1560 (2000).

R. R. Li, P. D. Dapkus, M. E. Thompson, W. G. Jeong C.

Harrison, P. M. Chaikin, R. A. Register,D. H. Adamson, Dense

Arrays of Ordered GaAs Nanostructures by Selective Area Growth on

Substrates Patterned by Block Copolymer Lithography, APPL PHYS

LETT 76: (13) 1689-1691 (2000)

Diblock Copolymer Nanolithography

Spheres

Cylinders

Lamellae

Monolayers on a substrate

collaboration with R.R. Li, P.D. Dapkus, and M.E. Thompson (USC)

use MOCVD to selectively grow GaAs dots on substrate, through holes in removable “mask”

GaAs

GaAs

GaAs

GaAs

GaAs

GaAs

polymer

SiNx

(15 nm)

ozone

MOCVD

CF4 RIE

wet etch

GaAs Dots Have Narrow Size Distribution

TMAFM tip

GaAs (001)

dot diameter

(FESEM)

height above

SiNx (TMAFM)

Number of Dots

diameter:

23 ± 3 nm

overall height:

14 ± 2 nm

tapping-mode

atomic force

microscopy

(TMAFM)

Size (nm)

395 K

466 K

Orientational Correlation length

Average Distance between Disclinations

2 ~ -1/2 t1/4

DEPTH PROFILING AN ISLAND

A

B

Fred, 0.5 point

blur. Figure 2.

TOP

MIDDLE

D

C

BOTTOM

500 nm

Nature Feb. 6,1965

For Circular area two loops are essential

Topological equivalent

Three loops and one Triradius

Two Loops

Analysis of a micrograph

100 nm

/3

0

Disclinations : “5” and “7”

Steps :

1.Locate Spheres

2.Triangulate Lattice

3.Locate disclinations

4.Locate dislocations

5.Create orientation field

6.Color-map

Measuring Correlation Length x6

- All sphere centers are located and the inter-sphere triangulation lattice produces the local “bond-orientation” angle.
- We define e6iq(x) as our hexatic order parameter to calculate x6, similar to x2.

Correlation Function

Images

09169878

250 nm

x6~130 nm~4.5 d0

Time Dependence of Correlation Length

t1/4

shift data by aT,

taking 398K as

reference

(nm)

t/aT

e:\papers\hexaticcoarsening\master 1

dislocations

Color

Lookup

Table

40nm

Step Edge

Mask

PS/PI

Substrate

Substrate

Without mask

With mask

S. Chou C. Harrison, P. Chaikin, & R. Register

Effect of Diblock Copolymers on the Quantum Hall Effect

a

T=0.3K

unpatterned

T=0.3K

patterned Vg=0.1

m

1

m

3.0

3.0

30

25

2.5

2.5

20

2.0

2.0

Hall Resistance Rxy (kW)

15

1.5

1.5

Longitudinal Resistance Rxx (kW)

Longitudinal Resistance Rxx (kW)

1.0

1.0

10

5

0.5

0.5

0.0

0.0

0

0

0

12

12

2

2

6

6

8

8

4

4

10

10

Magnetic Field B (T)

Magnetic Field B (T)

Chaikin, Register, Shayegan, Bhatt

The periodic modulation induced by the triangular polymer lattice lifts the degeneracy of the Landau levels, creating a commensurability-related sub-band structure (Hofstadter butterfly) which should cause extra peaks to appear in the longitudinal resistance.