Synchrotron X-Ray Laue Micro/Nanodiffractiontpsbl.nsrrc.org.tw/userdata/upload/21A/2017 XMAS...
Transcript of Synchrotron X-Ray Laue Micro/Nanodiffractiontpsbl.nsrrc.org.tw/userdata/upload/21A/2017 XMAS...
Synchrotron X-Ray Laue
Micro/NanodiffractionNobumichi Tamura
Advanced Light Source
Lawrence Berkeley National Laboratory
Fiber-textured Gold film
Garnet Laue pattern
Cu kossel lines
Si blisters
Outline
What is X-Ray Laue Microdiffraction?
- X-ray Laue (polychromatic) diffraction
with a small x-ray (~micron size) beam
What do you need to do X-Ray Laue
Microdiffraction? (Synchrotron radiation, X-Ray
Focusing Optics, Beamline, X-Ray Detector,
supercomputer…)
What information can you get from Laue
patterns?
- Crystal orientation
- Strain/stress
- Plasticity
Going 3D
A century old technique
Max von Laue (1879-1960)
Nobel prize in 1914
MEMS
Spatial resolution from microbeam allows for
mapping crystalline and mechanical properties of
small devices…
What X-Ray Laue Microdiffraction could
do for you (in a nutshell) ?
What type of problems can be investigated with x-ray microdiffraction?
Mechanical properties of materials at the inter and intra-granular
level
Ex: deformation processes in bulk materials, failure analysis
Mechanical properties of small devices (microelectronics,
MEMS & NEMS, etc.)
Ex: reliability issues in microelectronics
Spatially resolved characterization of heterogeneous materials
Ex: distribution of phases in soils, minerals, composites or
alloys
Applications in a wide range of fields, including materials science, microelectronics, geology,
earth science, biomaterials, archaeology, and nanotechnology.
Ferromanganese
concretions in a
soil sample
(Courtesy: A.
Manceau)
TWA800 crash
was due to fuel
tank fatigue
failure (Source
CNN)
Multilevel Cu
interconnect
structure
An overview of Scientific projects at the ALS Microdiffraction
beamline• Mechanical properties of materials
• Size effect studies: Nanopillar compression, Nanowires
deformation
• stress in Ni-based superalloys
• stress in Cu-Nb multilayers
• residual stress in dental crown
• tin whisker growth
• electromigration in Pb-free solder
• Environmental and Earth Science
• Precipitates in acid mine drainage
• Stress in shocked quartz
• Uranium speciation on contaminated sites
• Materials characterizations
• strongly correlated materials: VO2
• Novel materials: High pressure metal carbides and
nitrides, Zeolite structures
• Batteries: Lithium batteries, solid oxide fuel cells
• Archeological artifacts: Roman Terra Sigillata poteries
• Solid hydrogen polymorphs
• Characterization of biomaterials
Mechanics of Nitinol Endovascular Stents
A. Mehta et al. UCB, Advanced
Materials (2007) 19, 1183–1186
Gradual Ordering in Red Abalone Nacre
P.U.P.A. Gilbert et al. , JACS, 130(51) (2008)
17519-17527.
VO2 Stress-Temperature
Phase Diagram
Jinbo Cao et al., UCB , Nano
Letters, 10 (7) (2010) pp 2667–
2673
Novel Rhenium Nitrides
Alexandra Friedrich,et al.,
Physical Review Letters
105, 085504.
Strain-induced M1-M2 phase
transition in VO2 nanowires
Hua Guo,et al., Nanoletters,
11 (8), pp 3207–3213.
Structure and Mechanical Properties
of a Pteropod Shell
Taiji Zhang et al. , 2011. Angewandte
Chemie. 50(44):10361-5.
Mechanical properties of
indium nanopillars
Lee G. et al., Acta
Materialia, 58 (4) (2010)
1361-1368.
Laue X- Ray Diffraction
X-ray diffraction with polychromatic (white) x-ray beam
Zirconium, deformed 5%Some mineral in fly ash
X-ray (l)
X-ray
Detector
X-Ray diffraction basics:
measurement
Crystal“Bragg condition” is rarely
satisfied!
l
Note: X-ray Detectors of choice
today are area detectors !
Ewald
construction
2dhkl sin(q) = n l
X-Ray Crystallography
needs a usable set of
reflections… how to
achieve this?
2q
hkl
X-ray (l)
X-ray
Detector
Single
Crystal
“Conventional” Single Crystal X-
Ray crystallography
Debye-Scherrer rings
X-ray (l)
X-ray
Detector
Polycrystals
(“powder”)
X-Ray diffraction: measurement with monochromatic beam
“Powder” diffraction
l
l
Diffraction
cones
h1k1l1h2k2l2
X-Ray diffraction: measurement with polychromatic beam
Polychromatic
X-ray (Dl)
X-ray
Detector
Single
Crystal
l1l2
li
Laue diffraction
Bragg’s condition is
satisfied simultaneously for
many reflections => no
need to rotate the sample to
get a usable set of
reflections
Data collection is fast!
1/lmin
1/lmax
Ewald
Advantages of Laue X-Ray diffraction:
- No sample rotation required
- Data collection is very fast (sample mapping, time resolved experiments),
- No sphere of confusion problem for “small beams”
- Very small crystals
- Probed region is fixed
X-ray
Sample
X-ray
Sample
Single crystal
(macro)
Polycrystal (meso-
micro)
Polycrystal (micro-
nano)
YES YES NO
Laue X-Ray diffraction Caveats:
- Intensity interpretation is difficult => not routine for
structure solution
- Length of scattering vectors qhkl (wavelength) not a priori
known (absolute lattice parameters, hydrostatic strain)
- Crystal size has to be large enough (or X-ray beam small
enough) so that beam sees a “single crystal”!
The beamline and end-station
… Light, camera, action !!
Outside view from the ALS (photo: M. Kunz) Inside view of the ALS
The many advantages of using synchrotron radiation vs
a lab source…
- Orders of magnitude brighter x-ray
source
- Continuous wavelength spectrum
(Energy tunability) => x-ray
spectroscopy
- Highly collimated => spatial
resolution
- X-ray polarization => magnetic
material studies
- Time structure => time-resolved
studies
Lab source: 60 s
exposure
Synchrotron: 1 s
exposure
Data collected on a
same crystal at lab
source and
synchrotron
Faster data collection
Better angular resolution
Higher spatial resolution (x-ray focusing)
The many advantages of using synchrotron radiation vs
a lab source…
The Advanced Light Source at LBNL
3rd generation synchrotron source
construction started in 1987, runs since 1993
Synchrotron: beamlines at the ALS
source
M1 toroid mirror
shield wall
lead hutch
roll slits,
primary focus
virtual object
Si(111) 4 bounce
monochromator
JJ X-ray slits
aperture slits
KB mirrorssample
24.8 m24.665 m
24.53 m24 m22.4 m
13 m
ELEVATION
PLAN
source
M1 toroid mirror
Si(111) 4 bounce
monochromator
roll slits,
primary focus
virtual object
JJ X-ray slits
aperture slits
KB mirrors
sample
BL12.3.2: a dedicated Laue (polychromatic) X-Ray microdiffraction at the ALS
Detectors
Beam size on sample: 1 x 1 um2
Photon energy range: 5-24 keV (monochromatic or white beam)
• DECTRIS Pilatus 1M area detector
• Vortex-EM (SII Nanotech.) single element Si-drift fluorescence detector, 50 mm2 active area
• Sample mounted on a XYZ stage and a PI piezo stage
• c cradle for changing X-ray incidence angle
• Heating/Cooling stage
• Flexible positioning of sample and detector allow for both reflection and transmission geometries
Instrumentation: Sample stage, x-ray detectors
PI XY piezo stage
XY Nanomotion
stages
Huber χ cradle
Huber Z and φ
stages
• Laser triangulation sample positioning system (Keyence)
a) Fresnel zone plate, b) Multilayer Laue Lenses c) Bragg-Fresnel lens, d) Compound
Refractive Lenses, e) Waveguide, f) Kinoform lenses, g) multi-bounce capillary, h) single
bounce capillary, i) Kirkpatrick-Baez total external reflection mirrors, j) Multilayer mirrors in
KB configuration
X-Ray focusing optics
What X-Ray focusing optics to use for Laue X-Ray
microdiffraction?
Flux Density
Gain
Resolution
(nm)
Chromatic
aberration
Radiation at exit Scan in
Energy
Fresnel Zone
Plate (FZP)
~ 300 000 60-5000 (4-15
keV)
~ 1/l Monochromatic Possible
Bragg-
Fresnel Lens
(BFL)
~ 1000 100-5000 No Monochromatic Difficult
Compound
Refractive
Lenses
(CRL)
~ 500 ( l
dependant)
40-5000 ~ 1/l2 Monochromatic Difficult
Tapered
Capillary
~ 100 100-5000 No White or
Monochromatic
Yes
Kirkpatrick-
Baez Mirrors
~ 300 000 60-5000 No White or
Monochromatic
Yes
X-Ray
Waveguide
~ 500 ( l
dependant)
35-200 ~ 1/l2 Monochromatic Difficult
Flux Density Gain = Beam Compression Ratio x Efficiency
Reflective Focusing Optics
Kirkpatrick-Baez Elliptical
Mirrors
• Use total external reflection on two
orthogonal ultrasmooth elliptically
shaped mirrors
• Obtained by
• Bending of a flat mirror
• Differential coating of a spherical
mirror
• Further figure errors correction
by ion-beam sputtering, …
• Characteristics:
• Achromatic
• High efficiencyKB mirror system developed at the ALS
(bending of flat mirrors)
Synchrotron X-Ray Microdiffraction: other technical
developments
• Large area fast X-Ray 2D detectors:
capture in a single frame a large portion
of the reciprocal space
• Increase in resolution (smaller pixels),
efficiency, readout speed
• Diffraction scans in a reasonable time
Deformed Ta crystal diffraction
pattern
Dectris Pilatus 1 M
hybrid pixel detector
(1 M pixels, 179x168
mm active area)
MAR 165 CCD detector (2M pixels,
165 mm diameter active area)
Laue X-Ray Microdiffraction data
analysis
How to interrogate a diffraction pattern …
San Andreas Fault quartz Barium Titanite STARDUST
Laue patterns provide information on crystal structure, grain orientation, plastic and elastic strain.
What can we learn from a Laue (white beam) pattern ?
Laue X-Ray Microdiffraction:
methodology
The sample is scanned under a white X-ray
microbeam. At each step a diffraction (Laue)
pattern is collected with the area detector. A
preliminary X-ray fluorescence scan can be
used to precisely locate the region of interest
SEM image of an
encapsulated Al(Cu)
interconnect (4 mm
wide x 30 mm long)
Ti fluorescence mapWhite beam (Laue) diffraction
pattern of an Al(Cu)
interconnect. The brighter
spots are from Si wafer.
The indexation of the Laue patterns provide
the crystal orientation matrix of the area
illuminated by the X-ray microbeam. The
analysis of the entire scan gives the grain
orientation map of the sample.
Al grain orientation
map
Si spots from the wafer have
been digitally removed. The
remaining Al spots are
indexed.
Laue X-Ray Microdiffraction:
methodology
Measuring strain/stress with Laue X-Ray microdiffraction
Measuring “shifts” of the Laue reflection positions from their “unstrained” ones provide the deviatoric strain tensor.
Homogeneity property:
Transformation matrix:
Detector Detector
X-ray
Before compression After compression
Deviatoric strain:
Stress map
Laue X-Ray Microdiffraction:
methodology
Deviations of the Laue peaks positions from their “unstrained” positions provide the distortional strain tensor.
–Stress tensor: sij = Cijkl ekl
Plasticity effect on Laue peaks: GND and GNBs
Excess dislocations of the same sign (Geometrically Necessary Dislocations or GNDs) cause lattice curvatures that can be measured by Laue…
1) If GND are randomly distributed, the resulting deformation is equivalent to a pure bending
L
bθtan
Rb
1
Cahn-Nye Relation
2) Subgrains boundaries (GNBs) are the result of redistribution of dislocations in dislocation walls
1.- (1,1,1) [-1,1,0] [1,1,-2]
2.- (1,1,1) [-1,0,1] [1,-2,1]
3.- (1,1,1) [0,-1,1] [-2,1,1]
4.- (-1,-1,1) [-1,1,0] [1,1,2]
5.- (-1,-1,1) [-1,0,-1] [-1,2,1]
6.- (-1,-1,1) [0,-1,-1] [2,-1,1]
7.- (-11,-1) [1,1,0] [-1,1,2]
8.- (-11,-1) [-1,0,1] [1,2,1]
9.- (-11,-1) [0,-1,-1] [-2,-1,1]
10.- (-11,1) [1,10] [1,-1,2]
11.- (-11,1) [-1,0,-1] [-1,-2,1]
12.- (-11,1) [0,-1,1] [2,1,1]
Plasticity effect on Laue peaks: Active slip systems
Electromigration induced plastic deformation in Al interconnects
Accelerated test at 280 °C
g, b, t
Streak directions of the Laue spots provide information on the dislocation slip system
Shape of the reflections can be fitted to simulated reflections
Peak shapes provides information on plastic deformation
and dislocation distribution in the diffracted volume.
Cahn-Nye Relation
Pure bending
Subgrain boundary
Exp. Simul.Burgers vector and
dislocation line directions
can be derived from the
shape of the Laue
reflections (Barabash et al.,
2002 and 2003)
Dislocation density map
Laue X-Ray Microdiffraction:
methodology
Rb
1
L
bθtan
Grain orientation
Strain tensor
components
Dislocation density
Microstructure images generated from ~30,000 diffraction patterns
Scanning X-Ray Microdiffraction as a quantitative microstructure
imaging tool
X-Ray Microfluorescence/ X-Ray Microdiffraction combo
Fe Cu
Quartz Pyrite Chalcopyrite
Scanning X-Ray Microdiffraction
as a quantitative microstructure
imaging tool
Analyzing 1000s of
Laue patterns is
computationally
intensive
Bl12.3.2 uses NERSC supercomputing
facility to analyze Laue data
Shocked quartz (32,500 patterns analyzed
in 88 minutes on a 48 nodes cluster)
(Mis-) Orientation
Peak width
24 dual node
UNIX cluster
Going 3D
How to get depth resolution?
Al-sapphire composite (Bale et al., 2008)
-Broader energy bandpass
toward high energy allows for 3D
X-ray microdiffraction techniques
(depth resolution)
- 4 possible techniques:
- depth fitting
- triangulation
- wire scan (DAXM)
- diffraction tomography
Depth fitting: depth as a fitting parameter
X-rays
•Another white beam technique
•Given a certain geometry and
assuming certain angles between
reflections, depth can be included
as a “fitting” parameter
•The depth can be fitted
independently or with other
parameters (geometrical, grain
orientation, strain) using a least-
square approach.
N. Tamura, W.J. Choi and K.N. Tu, ALS/UCLA
Depth fitting: depth as a fitting parameter
Tilt angles of
CCD with respect to
incident beam
(2 par.)
Center channel
of CCD (2 par.)
Distance CCD-sample
(1 par.)
X-ray
CCD Camera
Sample
•Other parameters include:
•calibration parameters (5 parameters)
•strain (5 parameters)
•grain orientation (3 parameters)
•Parameters are refined
sequentially. Some are
determined using a
calibration sample
•Procedure requires
Laue patterns with large
number of spots
Whisker grain indexation =>
crystallographic orientation matrix
Z position (depth) fits => Angle between
whisker and sample surface
=> whisker growth direction (c-axis)
Application: what is the growth direction of a tin whisker ?
-0.51 -0.52 -0.53 -0.54 -0.55-0.74
-0.73
-0.72
-0.71
-0.70
-0.69
-0.5000
-0.4950
-0.4900
-0.4850
-0.4800
-0.4750
-0.4700
-0.4650
-0.4600
-0.4550
-0.4500
-0.4450
-0.4400
-0.4350
-0.4300
-0.4250
-0.4200
-0.4150
-0.4100
-0.4050
-0.4000
Y (mm)X
(m
m)
-0.74 -0.73 -0.72 -0.71 -0.70 -0.69 -0.68
-0.52
-0.50
-0.48
-0.46
-0.44
-0.42
-0.40
Z (
mm
)
X (mm)
surface
whisker
Depth fitting: depth as a fitting parameter
Data collection: fast (x 1)
Depth resolution: ~ 20-25 um
The Triangulation technique
H. A. Bale, J. C. Hanan, N. Tamura
Mechanical & Aerospace Engineering, Oklahoma State University,
Stillwater, OK
XZ
Y
XZ
Y
XZ
Y
Sample: 140 mm diameter
sapphire fiber in Al matrix.
Principle: white beam Laue
patterns at several detector
distances
40 mmThe triangulation
technique
50 mmThe triangulation
technique
60 mmThe triangulation
technique
70 mmThe triangulation
technique
80 mmThe triangulation
technique
•Triangulation consists in ray-tracing back
the reflections back to the sample.
•If several reflections from a grain are
known, all the reflections belonging to this
grain should converge to the point of origin
of the scattering rays.
•Algorithm:
•Reflections positions are fitted using
a 2D shape function
•Reflections are sorted out by grains
using multigrain indexation
•Diffraction patterns taken at several
distances are scaled and stacked
together (here 10 images/point)
•Point of origin (depth) of diffraction
for each grain (grain position) are
ray-traced backed.
•Strain is computed at correct depth
The triangulation technique
•Slices: cross section of
grains at certain depth
(show grain orientation,
strain)
•Depth +/- 25 mm accuracy
(depends on the number
of reflections, number of
image distances, …)
The triangulation technique
Depth resolution by
pattern correlation
between images
from different
distances
Sn sample
Data collection: moderate (x 5-10)
Depth resolution: ~ 5 um
The triangulation technique
The 3D Structural Microscope or DAXM (Differential
Aperture X-Ray Microscope)
Analytical procedure:
•Wire position with respect to the area
detector and beam position need to be
carefully calibrated
•Ray trace of outgoing beam is given by
position of wire when it extinguishes the
reflection and position of reflection on the
area detector. Depth from which the
intensity comes can be computed
•In order to have the right accuracy, b<<a
•Pixel intensities are sorted by depth. Laue
diffraction pattern from each depth is
reconstructed and can be analyzed
(orientation, strain, …)
Area Detector
Wire
a
b
X-ray
Developed at the APS (Larson, Ice et al., 2000)
Scanning wire used to sort detector pixel intensities
by depth
The 3D Structural Microscope or DAXM (Differential
Aperture X-Ray Microscope)
Use of a gold wire mounted on two scan
stages as a depth profiler
Example: Ni sample
The 3D Structural Microscope or DAXM (Differential
Aperture X-Ray Microscope)
Ni polycrystal
Data collection: slow (x 300-600)
Depth resolution: ~ 1 um
(-4,2,4)
Time to conclude …
Laue X-Ray Microdiffraction
- Laue X-ray diffraction
- X-Ray focusing optics (KBs)
- Synchrotron radiation
- 2D X-ray detector
Outputs:
- Crystal orientation, strain/stress, dislocation densities
Applications:
Non destructive (non-invasive) 2D (and 3D) mapping of materials
mechanical and microstructural properties.
Phase identification, ? Structure solution