Micro/nano SAXS/WAXS +
µGISAXS experiments at BW4
Small beams for small samples
Jochen S. Gutmann
Institute of Physical Chemistry, Johannes Gutenberg University, Mainzand
Max Planck Institute for Polymer Research, Mainz
Outline
• Personal motivation: Microcantilever sensors–
System
– Microfocus GISAXS
– Microfocus X-ray reflectometry
• Micro/nano SAXS/WAXS efforts at the HASYLAB
• Sumary
Outline
• Personal motivation: Microcantilever sensors–
System
– Microfocus GISAXS
– Microfocus X-ray reflectometry
• Micro/nano SAXS/WAXS efforts at the HASYLAB
• Sumary
What are micromechanical cantilever sensors?
Micromechanical cantilever principle
heat sink
heat source
calorimetric detection
U I
dynamic or gravimetric detection
surface energy changes, steric interaction, electrosatic interaction,conformational changes, structural phase transitions, stiffness change, volume change
static detection
R. Berger et al., Chem. Phys. Lett. 294, 363 (1998), R. Berger et al., Science 276, 2021 (1997)
Measurement principle Differences in surface stress
• static or surface stress detection
[σ]=N/m=J/m2Δσ=Ets2
6R �1− ν�t f1R≈ 3ΔV
2L2dzdV
-
one side coating of microcantilever-
uniform coating-
analysis of bending via Stoney’s formula (for constant radius of curvature)
σ1
σ2
σ1
− σ2
=Δσ
Central problems: All asymmetrically coated cantilevers are
„bimetallic elements“ All experiments show drift in the
nm/h range
Solution Incorporate references into your set-up
Micro cantilever arrays
A ‚novel‘ type of sensor•
Highly sensitive
(pg mass differences)
•
Easy to integrate•
Cheap (silicon) technology
But•
Coating may be difficult•
Physisorbed films may be washed off
•
Chemical grafting of polymer layer
How do we coat only selective cantilever surfaces?
Apply protective masks
Bare Cantilever
Evaporate gold on bottom
Evaporate gold on half of top
Use a shadow mask to protect half of the cantilevers
Graft starter for polymerization
O
CH 3O
BrSi
CH 3
OCH 3
Cl Si Br
OCH 3
O
NEt3
,Toluene
G.-G. Bumbu, G. Kircher, M. Wolkenhauer, R. Berger, J.S. Gutmann, Macromol. Chem. Phys. 205, 1713 (2004).
Polymer brushes via ATRP of methyl methacrylate
2EiBBr,
Anisole
MMA,
Cu/PMDETA
+ free polymer
BrO
CH3
Si
OCH3
O
O OCH3
[ ]n
Mn
(PMMA)=63kg/mol
G.-G. Bumbu, G. Kircher, M. Wolkenhauer, R. Berger, J.S. Gutmann, Macromol. Chem. Phys. 205, 1713 (2004).
Switching upon exchange of solvent environment
Why is cantilever #4 different?
Optical image
Only partial gold coating for cantilever #4?
Imaging ellipsometry? NO: because of gold
AFM imaging? NO: destructive for cantilever
How do we check layer parameters and mask homogeneity?
Enter microfocus GISAXS
Scattering geometry
Microfocus Grazing incidence scatteringBW4 beamline at HASYLAB (Germany)
λ=1.38Å
dsample-detector
≈1.9m
Resolution: qy
=3.8·10-4Å-1
Microfocus with Beryllium CRLs
Be CRLs
X-ray
Be CRLs
B. Lengeler, C. Schroer et al.; J. Phys. D: Appl. Phys. 38 A218–A222 (2005).
Matching the beam to the cantilever
Problem:At typical incidence angles we over illuminate by a factor of two.Solution:Only use partial beam
Alignment of cantilever
Height alignment in 10µm steps
5.5 5.545.52 5.56 5.58 5.6 5.645.62 5.66 5.68 5.7mm
µ-GISAXS scan
Position dependent gold coverage
M. Wolkenhauer, G.–G. Bumbu, Y. Cheng, S. V. Roth, J. S. Gutmann, APL, 89, 054101 (2006)
Microfocus X-ray reflectivity
dAu=10.3 nm ( ±0.5nm) dPMMA=10.4 nm ( ±0.5nm)
Lack of total reflection edge
M. Wolkenhauer, G.–G. Bumbu, Y. Cheng, S. V. Roth, J. S. Gutmann, APL, 89, 054101 (2006)
Do brushes remember solvent treatment?
Common finding:Different initial response after solvent switch
PMMA brushes Memory to (prior) solvent treatment
Memory to prior solvent in collapsed state
No memory in swollen state
G.–G. Bumbu, M. Wolkenhauer, G. Kircher, J. S. Gutmann, R. Berger, Langmuir 23, 2203 (2007).
µ-GISAXS investigation of PMMA brush swelling
Brush layer thickness varies between 32.5nm and 34.5nm
Modelling: Parratt32, HMI0,05 0,10 0,15 0,20 0,25 0,301E-9
1E-5
0,1
1000
1E7
1E11
1E15
Bare Si cantilever Bare Si cantilever no solvent THF Toluene Ethylacetate Isopropanol no solventR
eflectivity (arb. units)
qz (Å-1)
Evidence for interfacial correlations
0,06 0,07 0,08 0,09 0,10
1E-5
2E-5
3E-5
4E-5 B no solvent B Toluene
Inte
nsity
[cts
.]
qz [Å-1]
µGISAXSLateral (surface) structures
Outline
• Personal motivation: Microcantilever sensors–
System
– Microfocus GISAXS
– Microfocus X-ray reflectometry
• Micro/nano SAXS/WAXS efforts at the HASYLAB
• Sumary
µSAXS @ PETRA-III MissionDetectorµUSAXS
76.7m±500mm
81.7±500mm
61.5m 94m
Focus 70x150µm2
on detector
CRLs: N=4Radius 0.6mm
DC-MC
µSAXS2
Focus 17x10µm2
CRLs: N=9 -
56Radius 0.2mm
DC-MC
µSAXS1
Focus 42x20µm2
CRLs: N=4 -
25Radius 0.2mm
DC-MC
nSAXS
100mSample:
DC-MC Focus 0.1x0.1µm2
Sample: 85m
Sector 2, ID: P03•U-29, high-β
Large-offset DCM•Si 111•vertical offset -490mm•Fixed exit•Traverse path: 1300mm•8keV≤E≤23keV
Multilayer DCM•W/B4
C (10keV), 2nm•Mo/B4
C (13keV), 1.5nm•vertical offset -500mm•Fixed exit, fixed angle
Harmonics suppression Mirror•Quartz substrate•length: 600mm•Fixed exit double mirror•fixed angle: 0.13°•vertical offset -10mm•Two additional coating: Pd, Mo•8keV≤E≤23keV
Design
Components
Visit near BW4
Test using 63 BeCRL at BW4
MicroscopeSlit
SampleMirror
50mm
Design underway
Resolution - µUSAXS, µSAXS1, µSAXS2
µUSAXS: 70x150µm2
µSAXS1: 42x20µm2
µSAXS2: 17x10µm2
BW4
2nm…10µm
Bhat, Nanotechnology 14 (2003) 1145–1152
100µm … cm
Nanofocus end station EH2
nanofocus EH2•Nanofocus end station•SAXS/WAXS•B=100x100nm2
Control hutchFor EH1 & EH2
Climate Lock nSAXS
Climate condition:hutch operated independently
Outline
• Personal motivation: Microcantilever sensors–
System
– Microfocus GISAXS
– Microfocus X-ray reflectometry
• Micro/nano SAXS/WAXS efforts at the HASYLAB
• Sumary
Summary
µfocus GISAXS•
Scattering on very small samples •
Reflectivity measurement possible•
Off specular scattering possibleprobe lateral structures and interfacial correlations
Petra - III•
Be CRLs Microfocus•
Zoneplates Nanofocus•
µSAXS, µWAXS, µUSAXS and µGISAXS capabilitiesMicrofocus Extras•
Colinear microscope view•
(Semi-automatic) datatreatment
Thanks to
Dr. Y.-Y. Cheng S. NettDr. M. Wolkenhauer
S. LenzDr. G.-G. Bumbu M. Memesa
Dr. R. Berger
Dr. S. V. Roth (HASYLAB)
Prof. Dr. H.-J. Butt
Funding Exp. Facilities
Max-Planck Society, BMBF
HASYLAB
AGFA, IWT
EU-MCTS
DFG
Thank You
and remember…..
cantilever stones ....
...don‘t deflect
cantilever stone, Glyder Fach (Wales)