Dept. of Chemical E'[,r1C
SECURITY CLASSIFICATION OF THIS PAGE
REPORT DOCUMENTATION PAGE la.
ih
REPORT SECURITY CLASSIFICATION
Unclassified 2a.
RESTRICTIVE MARKINGS
I DISTRIBUTION/AVAILABILITY OF REPORT
SECURITY CLASSIFICATION AUTHORIIY
Unclassified/Unlimited IB. DECLASSIFICATIOWDOWNURADINU SCHEDULE
Technical Report ep< #12
7a. NAME OF MONITORING ORGANIZATION
ib. OFFICE SYMBOL (if applicable)
Sa. NAME ÖF PERFORMING ORGANIZATION TÜR
ro
3. MONITORING ÖRGANF/ATION REPORTNUMBERS
4. PERFORMING ORGANIZATION REPORT NUMBER^
University of Minnesota
Office of Naval Research
6C. AÜÜRESS (City, State, and Zip Code)
78. ADDRESS (City, State and121p Coie)
800 Quincy Street North Arlington, VA 22217-5000
Dept. of Chemical Engineering &Materials Science University of Minnesota Minneapolis, MN 55455 8b. OFFICE SYMBOL Sa. NAMEiovi OF FUNDING/SPONSORING ORGANIZATION (if applicable) ONR Office of Naval Research
i). PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER
Contract No. N/N00014-93-1-0563 10. SOURCE OF FUNDING NUMBERS
8c ADDRESS (City, State, and"Zlp Code)
PRÖ1ECTNÖ. PROGRAM— 800 Quincy Street North ELEMEHTNO. Arlington, ngt VA 22217-5000 TTTTTLE mrt(Include Security Classification) Epitaxial Interactions Between Molecular Overlayers and Ordered Substrates
TASK NO.
WRKUNTT ACCESSIONNO
irPERSONALAUlWR(S)
Andrew C. Hillier and Michael D. Ward lia. TYPE OF REPORT
Technical
lib. TIME COVERED FROM 5/11/95 TO 6/30/96
U. DATE Of REPORT (Year, Month. Day)
13. PAGE COUNT
96/5/13
26
16. SUPPLEMENTARY
to be published in Phys. Rev. B L
17. T7H2T
C0SAT1 CODES GROUP
IS. SUUJtC'lltKMS (Continue on reverse if necessary and identify by block number)
SUB-GROUP
Organic Condustor, Atomic Force Microscopy, Nucleation, Epitaxy
K. ABSTRACT (CONTINUE ON REVERSE AND IDENTIFY BY BLOCK NUMBER
'
A framework for evaluating the epitaxy of ordered organic overlayers of generic symmetry on ordered substrates is described that combines a computationally efficient method for explicit determination of the type of epitaxy (i.e., commensurism, coincidence, or incommensurism) and overlayer azimuthal orientation with an analysis of the elastic properties of the overlayer and the overlayer-substrate interface. The azimuthal orientations predicted by this function agree with values predicted by semi-empirical potential energy calculations and observed experimentally for previously reported organic overlayers which are demonstrated here to be coincident, including electrochemically grown overlayers of molecular conductors. Calculations based on this analytical approach are much less computationally intensive than potential energy calculations as the number of computational operations is independent of the overlayer size chosen for analysis. This enables analyses to be performed for the large overlayer basis sets common for molecular overlayers. Furthermore, this facilitates the analysis of coincident overlayers, for which the overlayer size needs to be large enough to establish the phasing relationship between the substrate and large non-primitie overlays supercell so that the global minimum with respect to azimuthal angle can be determined. The computational efficiency of this method also enables convenient examination of numerous possible reconstructed overlayer configurations in which the lattice parameters are bracketed around those of the native overlayer, thereby allowing examination of possible epitaxy-driven overlayer reconstructions. When combined with calculated intralayer and overlayer-substrate elastic constants this method provides a strategy for the design of heteroepitaxial molecular films. 21. ABSTRACT SECURITY CLASSIFICATION
20. DlSTRlBlfTlON/AVAlLABlUTY OF ABSTRACT l-J UNCLASSIFIED/UNLIMITED U SAMEASRPT 22a. NAME OF RESPONSIBLE INDIVIDUAL
Michael D. Ward DD FORM 1473, 84 MAR
D
OTIC USERS
Unclassified
22b. TELEPHONE (IncUe Area Code)
22C. OFFICE SYMBOL
(612) 625-3062 83 APR edition may be used until exhausted. All other editions are obsolete.
SF.CUR1TY C1ASSIFICAT1QN OF THIS PAGE
Unclassified
Due QTJAUTY uaawscTED l
THIS DOCUMENT IS BEST QUALITY AVAILABLE.
THE
COPY FURNISHED TO DTIC CONTAINED A SIGNIFICANT NUMBER OF PAGES WHICH DO NOT REPRODUCE LEGIBLY.
OFFICE OF NAVAL RESEARCH Contract N00014-93-1-0563 Technical Report No. 12 "Epitaxial Interactions Between Molecular Overlayers and Ordered Substrates" by Andrew C. Hillier* and Michael D. Ward to be published in Phys. Rev. B Department of Chemical Engineering and Materials Science University of Minneapolis 421 Washington Avenue SE Minneapolis, MN 55455 May 1996 Reproduction in whole or in part is permitted for any purpose of the United States Government. This document has been approved for public release and sale; its distribution is unlimited. ♦Current address: Department of Chemical Engineering, University of Virginia, Charlottesville, VA 22902.
- i 'a 8 = -a a. -s
1*11 s I 3 I
ä
!g
|
.3,
1
3
3
-S"
J
8
a
e
1
1 2a.
'
200 a
3
3
i-
=
3.
ö
(2
-^ 9£
a
S u
a .a I I z o
u 8
>,
ö
3
S
| .3 _
a
a
3
8. o
a « ö
IM
o.
■a
so o
1
5 vl
3
.2
O
J2
J I
3
i 1
I a
3 ! u JO S3 «n
a
-a
3
-a
■5
-Q
■s
& s-
■-
s
'S 1a -s
1
aa. -aI fi a
■s
s
£
& JS
s =
3 S. a ,8 ^
3 so
1 I
'5
i
I 1 1
1
IS.
I :s
ao
> 'S o 2
a
*-§•
s a
a £ 9) 09
fa
o
ä o ■a u a s C1 L, 01
«li
a
M
V
>. a
a
la
s
1
M
s
■|81St
ü *
So—*
■a
a d
> a 0 «* M
^§
I
J3
U
•llli 3
St
•«
< s o
E -o
3
s
a
a
.a2
z
i
3
E2
u
8
2
.S
«5 -1
S *
3
§ -2
2S
8
o ■a ■a o
a a u
£
«1
>i
o
* ^ c
=
ä CO -Q 3
*
"3 -9
a u
•a
V)
'SB
U
a
a
&
a
*"
2
C
a
o
3
*
>
■a
a. S
I
a
A
8"
~
u
SQ.
1
e
8. a
■a
a 5
S a. &
as. ^s
s -3
a
a * Z .3 < 3 as jj a ö
o
•■s 5
S, ■a
I
1
9 z
Z
■ a
o "i
&
oo
>>
* a
.§ 3
°?
S
11
< o
■a
a i S 1
i
2 I
.1
i i.3 a
S
2
—
3
O
2
3 .2 a
a —
>
> s § o S
I 1 a
*
& I» I3
2
B
j
u
o 3
J5
a
"I
5
1
i.o
1 a
S2
U
8 §
: i
o
a
■§
u
a
•a S
u
ha
18 I
rt
o. u u
1 s-
1 i
g
o
I I
a
1
1 *
S
a
|
a
DO
■S
a a
BO
>«
•a c
■9 1 9 I
-au
| £
f 2 U
5
ä
s
• eu
.2 "S
s
°
-5- ■£*
1
1 I
8
.1 ■a
1s
3
fS
1
I
3
a 0 BO
ajS
.3 S
S
.3
3
B
Ia .S*
1 i
a
e
a
c ■a
§
i
a
a
^
1 I
w w-
1 I
3
■o
> 1 -I 5I
a
1 S .3
a
S 6
f I
a
2 8
8
I t I
.3
I ^
ö
o
(S
a
8
§
a
a
-5
■o
a >
o c
s
3 ■—*
9 a o
3 ■a o
1
I '3 ■a
a
4)
E
00
Ö+
>
V-a
f—-.
5
=
I II
s
9w
+
§•
i
•
w-
1 11
1 .ss?
«i
3
o II
■■o
* S.
*la?
U
,£>
■§3
ES
7
5 a
.3 .a 1
-3 •=
a 1
ü
.3
— o
+
SP
II
ail I1 2?i" z1
+ IN
-i(N II
u
ä
+ .3
s
'= ^
1 1 2 o
«5 nS
8-
i 2
■
=
.5
5 vi « ■a >o
c
ST'
is"
JÜ Ö-
"O
t-
™
a 5: >
3
5
TS
^
1 i
+4 o*
SI«
II
£* £*
i 9
I c
o
II
i
.a
2
>
-a
a
a
w
£•
>
2
MI
i£
■-
*•
.S
CL
>
rt u >. ^
•s
1 su
>
a
i o
1»
e CJ
P-
ä £ . a
2
c
■ft
a 8
ao X u 3 3 3 o.
2
u
"i
2
5
II
3 5
1
300
300
■9
a
ä
8
~
■=
&
.3
&
5
>•
!
*
e
1
Ö
s
5 W
I 1.
■a
.8
5 .8
i £
U
i
K o
S *
S 2 .6 2
£2222222i2 3,£ §=§=§=2=22 a a 3 ^ ff B
Qü
a u
a u
n«
ü§£"
H
0.
o •o
.3
.ü
c o
w)
ja
1?
=
a s
3.
u
s o
5 o
s
u
o
2
'2
.5
S
w
-
■a
1
s
a
3
3
1
S
^
a
£ i 'S aZ ■a s 8.
a e o ä
3
>t
o
S 0
S
5
u
?
ao
a
.2
_
«i
£
8.
.S
."
S
-S
1 I
i
0
1 I &
if —
2P S 3
ä
i>
.a
M
-s
S
I § ■*
8.
3
8
Jj 5
3
a
a.
e
CO
■g
Z
1?
- 1
is ■o
s
I■c 8 a f
'3 a
rt
3
ha
na
i
■o
.3
'" 1 I .1a ~I |3
ö ■3
a
■a
8
a0
u
-a
s
■a
3 tM
a
3
o
b
K (*>
S S 3 .aa .3 9 .a« Ö
o
I 1 s
M Uj
rt
a ■5
—
a l
■ao
■o
a
§
s
I 1 1 1
on
.3
ff ?
u
=0
-5
§ I a 00 s I ■~
-s
8. 5
I
1
Ä
•a
^
tu
>
o O
oO. "2. ^
-
o
.a
3
S
■s
3 00
•■I id
.3
5
5
3
"8
lit -a
i
■a 2
I
•< a5 S°
1S .s
a .3 CO CO
I
— "
QO
" M
U
a. 0
2
>*
oo
*-
8
In
o
oo
■5
>
O
H Z fid
J
S fid U
S
ä
Q Ed -1
■a
I
7T
3
•
9
,8 o
S 1
Z
3 3
a,
". *
VI
1 1■s
i
r>
u
i£
o
00
S
o
tä
8
•5
s •a
■o
u
> 3a
1
S
3!
.3
3
-5 .8
a
13
M
"3cfl
n
-2!
5
n
-3
s o
S
-I
J2
.—.
~
«
W
0
::::::
^
OQQQQQOOOO OOOOOÖ®®® (5®®®®® ggggoo 000$®®® ®®®QQ ooo ®®®®®
®®ggggo ooooo ggggooo 0006©®®
o
^■NOOOO^CMO
O
OOOOOOOOOO 0®0®0®0®0® OOOOOOOOOO 0®0®0®0®0® OOOOOOOOOO 0®0®0®0®0® OOOOOOOOOO
CD
o®o®o®o®4^® OOOOOOQOQOJ. o®o®o®o®e® CM (0
Tfcvjqoqcq^cvjq T^T^T-^ddddo
CO
V
-3.55
(kcal/mol) -3.65
D(G)
V Vo
.■-T
9.68
-9.68
-9.68
/^
i
1
ia-^7-V-1—
" .?r q 3o"'
2 i | K -V T+1 P
~V
^a,+ r
wsm
XX XXX
'?"
^
1.—
1
1
1
1
o CO
o CO
o
o in
