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)
Transcript
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 ofhard-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, 1999F. 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, DenseArrays of Ordered GaAs Nanostructures by Selective Area Growth onSubstrates Patterned by Block Copolymer Lithography, APPL PHYSLETT 76: (13) 1689-1691 (2000)
Diblock Copolymer Nanolithography
PB
50 nm
SILICONSUBSTRATE
PB
PB
SILICON
60 nm
Lamellae
Cylinders Spheres
polymer B
Diblock CopolymerIn bulk and at equilibrium, diblock copolymers exhibitmicrophase separated morphologies due to theincompatibility between two blocks and connectivityconstraint, and self-assemble in well ordered structures.
Spherical
Cylindrical
Lamellar
SA
CA
L~10Disordered
0.5 fA
XN
SA CA
LSBCB
X=Flory Huggins Interaction ParameterN=Degree of PolymerizaionfA=Volume Fraction of A Block
Monolayers on a substrate
PB
50 nm
SILICON
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
ozone
CF4 RIE
MOCVD
wet etch
polymer SiNx (15 nm)
GaAs GaAs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 300
10
20
30
40
50
60
70
height above SiNx (TMAFM)
dot diameter(FESEM)
GaAs (001)
TMAFM tip
GaAs Dots Have Narrow Size Distribution
Num
ber
of D
ots
diameter:23 ± 3 nm
overall height:14 ± 2 nm
tapping-mode atomic force microscopy (TMAFM)
103
104
105
106
102
103
2(nan
om
eter
s)
Annealing Time (seconds)10
310
410
510
6
102
103
-1/2 (
nan
om
eter
s)
Annealing Time (seconds)
Orientational Correlation length Average Distance between Disclinations
• All sphere centers are located and the inter-sphere triangulation lattice produces the local “bond-orientation” angle.
• We define e6i(x) as our hexatic order parameter to calculate 6, similar to 2.
~130 nm~4.5 d0250 nm
Correlation FunctionImages
0 500 1000
0.0
0.2
0.4
0.6
0.8
1.0
B 09169878
g6(r)~e(-r/)
nanometers
Time Dependence of Correlation Length
104
106
108
10
100
6
Time/(a2/D)
104
105t1/4shift data by aT,
taking 398K as reference
t/aT
(nm)
ColorLookup Table
40nmStep Edge
dislocations
“perfect alignment with Mask and Pressure
Substrate
Without mask
Mask
Substrate
With mask
PS/PI
S. Chou C. Harrison, P. Chaikin, & R. Register
Effect of Diblock Copolymers on the Quantum Hall Effect
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.
