Recent Science with
Synchrotron Radiation
Sunil K. Sinha
UCSD
Cheiron School 2011 Lecture

Science with X-Rays
•
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•
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Diffraction and crystal structures
Structure Factors of liquids and glasses
Structures of Thin Films
ARPES
EXAFS, XANESStudies of Magnetism with resonant XMS
Inelastic X-ray scattering: phonons, electronic excitations
X-ray Photon Correlation Spectroscopy
Microscopy
Imaging/Tomography
Pump-Probe Studies

Example 1: X-Ray Diffraction & structural biology• D.C. Phillips presents the
3-D structure of lysozyme
to the Royal Society in 1965

• Linear polypeptide chain• Folded model of the sameamino acid sequence• July 2009:
58,588 structures inProtein Data Bank

A single protein structure used to be the project of a scientific lifetime
Synchrotron Radiation - 8301 structures solved in 2009

X-rays dominant in protein structure determinations

Basics	
  of	
  Resonant	
  X-­‐ray	  Magne3c
Sca5ering
QZ

Detector
Field

Linearlypolarized
X-ray

α

β

f
Incident x-rays are tuned to
the M edges of rare earth
element (in this case Dy)d

The scattering factor in the dipole approximation is given by,

3
3
)
1
1 &
f = (e .ei )(! re Z + *[ F1 + F!1 ]% + *i(e*s # ei ) " m[ F!11 ! F11 ] + (es* .m )(ei .m )[2 F01 ! F11 ! F!11 ]
8+
'
$ 8+
*
s

fC - charge

scattering factor

fm - magnetic
 Iσ ∝ | f C|2 + | fm|2

scattering factor

 Total	  signal	
  is	
  combina.on	
  of	
  charge	
  and	
  rela.vely	
  weaker	
  magne.csignal.	
  For	
  charge	
  forbidden	
  Bragg	
  peak,	
  signal	
  is	
  dominated	
  by	
  magne.ccontribu.ons.
 The	
  signal	
  in	
  the	
  case	
  of	
  Dy	
  is	
  due	  to	
  an.ferromagne.c	
  Bragg	
  peak.

Depth Dependent Magnetic Density Profile

2.0

Co
Fe
Fe RotFe PinNet Mag

1.5

0.06

0.00

1.0

1.2

HE = 0.18 T

-0.06

0.5

-0.12

-0.2

0.0

0.2

0.4

0.6

Applied Field (T)

0.0

-0.5

Co
Fe x15

I+ - I-

1.8

Magnetizationµ! (/atom)

Magnetizationµ! ( /atom)

0.12

0

100

0.6

200 300 400
Depth (Å)

500

Co

100 %
65 %
08 %

0.0

06 %

0

75

150

Depth (Å)

225

FeF2

Exchange bias due to exchange interaction between Fe pinned and Co
moment across the Co/FeF2 interface.

Polarons via single-crystal diffuse scattering2

18.0(2,0,0)(0, 0, l)(0, 0, l)

0
-1

16.5

-2
-2.2 -2.1

16.0
0.8

-2.0 -1.9 -1.8

(h, 0, 0)12(0,0,10)
11(0, 0, l)

17.0

10
9
-0.2 -0.1 0.0 0.1 0.2(h, 0, 0)

0.9

1.0

(h, 0, 0)

1.1

1.2

L. Vasiliu-Doloc et al., PRL 83, 4393 (1999).

17.5

1

8

(1,0,17)

TOPOLOGICAL INSULATORS AND DIRAC POINTSPhase Contrast Imaging
PEEM
X-ray tomography
X-ray Microscopy/Fluorescence microscopy
X-Ray Holography
Phase retrieval imaging

COHERENT X-RAY BEAMSCoherence Lengths

ξl = λ2 / Δλ= λ(Δλ /λ)-1ξt = λ R / s(ξhor., ξvert.)

First X-ray Speckle:

M. Sutton et al., Nature 352, 608-610 (1991)

A. L. Schawlow “Laser Light"

Scientific American, 219 (3), p. 120, (1968)

Imaging via Soft X-ray
Fourier Transform Holography

aperturereference

sampleneeds circular polarized x-rays
Method : S. Eisebitt et al. Nature 432, 885 (2004)
Resolution: L. M. Stadler et al. PRL, 100, 245503 (2008)

Photon Correlation
Spectroscopy
Brownian Motion of 100 particles

Intensity-intensity auto correlation
1.15

g 2 ( q,! ) =I ( q, t ) I ( q, t + ! )1.1gI ( q, t )

2

2

1.05

1
0
10

10

1

10
delay

2

10

3

Diffraction Pattern

SpecklesPhoton Correlation Spectroscopy
coherent
beam

sampledetector

X-ray speckle pattern from a static silica aerogel

Siegert Reln.
g2(q,t) =⎥ g1 (q,t)⎥ 2

T. Thurn-Albrecht et al., PRL 1996

SURFACE/INTERFACE DYNAMICS

Perfect & Imperfect „Mirrors“

Statistical Description of Surfaces• Surface profile!
!
z( r|| ) = z + !z( r|| )• Height-height correlation function for a homogeneous,isotropic and ergodic surface
C(R, ! ) = " z(0)" z(R, ! )• FT[C(R)] measured in a surface scattering experiment1.10

Intensity
Autocorrelation-1

q||= 3.85E-3 nm! = 124.0 sec

1.05
1.00
1.10

-1

q||= 5.87E-3 nm! = 36.1 sec

g 2 ( q,! ) =I ( q, t ) I ( q, t + ! )I ( q, t )g 2 ( q,! ) = 1 + " e # 2 t / !

2

g2

1.05
1.00
1.10

-1

q||= 8.92E-3 nm! = 7.8 sec

1.05
1.00
1.10

-1

q||= 1.23E-2 nm! = 1.5 sec

1.05
1.00
0.1

1.0

10.0

time delay (sec)

100.0

Hyunjung Kim, et.al., PRL 90, 68302 (2003)

Relaxation of Over-damped Capillary Wave
(Thick Films h>>Rg)

Over-damped relaxation time constants
Thickness scaling% # (% 1 ([cos(q|| h) 2 + (q|| h) 2 ]! (q|| ) " 2' *' *& $ )& q|| ) [sinh(q|| h)cosh(q|| h) + q|| h]!
= f (q|| h)hη: shear viscosity
γ: surface tension
h: film thickness

 J. Jäckle, J. Phys: Condensed Matter 10, 7121 (1998)
 H. Kim, et al., Phys. Rev. Lett. 90, 68302 (2003)
 Z. Jiang, et al., Phys. Rev. E 74, 11603 (2006); M.L.Henle and A.J.levine, Phys. Rev. E 75,021604 (2007)

What happens as we lower thetemperature to near Tg?
Z.Jiang et al. Phys. Rev. Lett. 101, 246104 (2008)

“Apparent” Shear Viscosity•••

Consistent with bulk values from rheological measurements at T>>Tg.
Orders of magnitude less than bulk values and independent of Mw near Tg.
Intersect with reptation theory (η∝Mw3.4) at Mw*– Mw* =Mc (Mc=31.2k g/mol: critical molecular weight for entanglement).

•

Same Mw* found at 106 ºC, where surface dynamics are 7 times slower.

G $$(" )! = lim" #0"

Z.Jiang et al., PRL 2008

F. C. Frank, Proc. R. Soc. London A 215, 43 (1952).
P. J. Steinhardt, D. R. Nelson, and M. Ronchetti, Phys.
Rev. B 28, 784 (1983)

P.Wochner et al.
PNAS 2009

XPCS on Magnetic System – Provides
Information about Domain Dynamics
 XPCS	
  can	
  study	
  slow	
  dynamics	
  ranging	
  from	  milliseconds	
  to	
  hours	  magne8c	
  domain	
  mo8on	  or	
  cri8cal	
  slowing	
  down.
 Limited	
  XPCS	  work	  in	
  magne8c	
  system	  has	  been	
  reported.
	
  	
  	
  	
  	
   Shpyrko	
  et.	  al	
  –	
  Nature	
  447,	
  68	
  (2007)	
  	
  Study	
  of	
  AF	
  Cr
	
  	
  	
  	
  	
   Seu	  et.	  al	
  –	
  PRB	
  82,	
  012404	
  (2010)	
  	
  Study	
  of	
  ultrathin	
  Co
Konings	
  et.	  al	
  –	
  PRL	
  106,	
  077402	
  (2011)	
  	
  Study	
  of	
  Ho
A	
  suitable	
  system	
  needs:
a. Reﬂec8on	
  geometryb. Not	  too	
  small	
  in	
  Q	
  –	
  contamina8on	
  by	
  charge	
  roughness
scaLeringc. Not	  too	
  large	
  in	
  Q	
  –	
  would	
  not	  be	
  able	  to	
  reach	  with	  soM	  x-­‐
rays.

The	  Sample:	
  Y/Dy/Yo Hexagonal	
  laGce.	
  SpiralanJferromagneJc	
  phase	  between	
  TC(~85K)	
  and	  TN	  (180K).
o MagneJc	
  scaSering	
  is	
  enhanced	
  atresonant	
  edge	  (M5	
  1305eV)	
  and	  themagneJc	
  diﬀracJon	
  peak	  can	  beseen.
o Domains	
  are	
  formed	
  in	
  single	
  layer,with	
  diﬀerent	
  chirality	
  and	
  defects
etc.
8ML	
  spiral,	
  turning	
  angle	  45o

Temperature	
  Dependence	
  of	
  the	  Spiral	  An8ferromagne8c	
  Bragg	
  PeakY/Dy(500nm)/Y	
  trilayer(0,0,0.2)	
  Bragg	
  peako Reported	
  TC	
  is	
  about	
  85K,	
  but	
  magneJc	
  diﬀracJon	
  peak	  does	  notdisappear	
  unJl	
  65K.
o DiﬀracJon	
  peak	  vanishes	
  at	
  reported	
  TN	
  =	
  180K.

Temperature	
  Dependence	
  of	
  the	
  Turn	  Angleo Turn	  angle	  changes	
  from	
  50	
  degrees	
  at	
  180K	
  to	
  31	
  degrees	
  to	
  64K	  –change	  of	
  AF	
  Bragg	
  plane	  distance.

Temperature	
  Dependence	
  of	
  Correla5on	
  Length

TC	
  ~	
  85K

Single	  Lorentzian	
  ﬁt	
  to	
  the
magneIc	
  Bragg	
  peak.

TN	
  =	
  180K

Sta5c	  Speckles
T	
  =	
  77K	  (near	
  TC)

T	
  =	
  141Ko From	  temperature	
  near	
  TC	
  (1st	  order	  phase	  transiIon)	
  all	  the	
  way	  tonear	
  TN,	  the	
  speckles	
  are	
  staIc.	
  No	
  dynamics	
  observed.

Dynamics	
  near	
  TN
T	
  =	
  170KT	
  =	
  178.4K

T	
  =	
  179.0K

XPCS

Diffraction Imaging

The “Phase Problem”

Miao, Charalambous, Kirz, Sayre, Nature 400, 342 (1999).

λ=1.8 nmsoft x-ray
diffraction
pattern

Low angle data
From optical
micrograph

Scanning
electronmicrographof object

Image reconstructedfrom diffraction
pattern (θmaxcorresponds to 80
nm). Assumed
positivity

Reconstruction
Equations can still not be solved analytically
Fienup iterative algorithm

Reciprocal space•Positivity ofelectrondensity helps!
9/25/11

Imposediffraction
magnitudes

Miao thesis

Real space

Imposefinitesupport11

JCHS 7

Successful reconstruction of image from soft X-ray speckle alone.
SEM Image

X-ray reconstruction

50 nm diameter Gold Balls on transparent SiN membrane.

No “secondary image” was used
Approximate object boundary obtained from autocorrelation fn.
*How to make an isolated object ? Use AFM to remove unwanted balls.

.

He, Howells, Weierrstall, Spence Chapman, Marchesini et al. Phys Rev B In press. 03, Acta A.59, 143 (2003)

Imaging of individual nanoparticles at the
APS
Ross Harder, University of Illinois, Champaign
Coherent diffraction patternfrom 170 nm Ag particle

170 nm silver cubes

inversion ofdiffraction pattern‘lensless imaging’

I.K. Robinson, et al., Science 298 2177 (2003)

•

•

•
•

Atomic resolution
structures known
for few mammalian
membraneproteins!
Collect many single
molecule diffraction
patterns from fast
x-ray pulses, andreconstruct?
Lysozyme explodes
in ~50 fsec
R. Neutze et al.,Nature 406, 752(2000)

Single molecule
imaging?

Single mimivirus particles intercepted and imaged with
an X-ray laser
Beyond	  crystallography:	  	  A	  new	
  world	
  in	
  structural	
  sciencesab1•A very short and extremely bright coherent X-ray pulse
can be used to outrun key damage processes andobtain a single diffraction pattern from a large
macromolecule, a virus, or a cell without the need forcrystalline periodicity.
•Mimivirus is the largest known virus, comparable in size
to a small living cell. It is too big for structure
determination by electron microscopy and it cannot becrystallised.

c0

200 nmde

1•The structure of the intact virus was recovered from theflash diffraction pattern alone.
•There was no measurable sample deterioration.
•Death-rays: We expect high-resolution structures insuch experiments with shorter and brighter photon
pulses focused to a smaller area.

1000 nm
0f

200 nmg•Resolution can be further extended by averaging forsamples available in multiple identical copies.

10

Linac	
  Coherent	
  Light	
  SourceD.	
  Wang	
  et	
  al.,	
  SF.R.N.C
cience	  3 24,	
  5931	  (2009)	
  et• al., Nature 470, 78–81 (2011)
M.M. Seibert, T. Ekeberg,
MaiaFemtosecond x-ray nanocrystallography overcomes
limitations of radiation damage
A	
  new	  paradigm	
  opens	
  up	
  macromolecular	
  structure	
  determina7on	
  to	
  systems	
  too	
  small	
  orradia7on	
  sensi7ve	
  for	  synchrotron	
  studies,	
  and	  may	  save	  years	
  of	
  eﬀort	  in	
  crystalliza7on	
  trials• The	
  ultrafast	
  LCLS	  x-­‐ray	
  pulses	
  allow	
  us	
  torecord	  “diﬀracIon	
  before	
  destrucIon”
where	
  informaIon	
  is	
  obtained	
  before	
  theonset	  of	
  structural	
  damage.
• DiﬀracIon	
  can	  be	
  measured	
  from	  sub-­‐
micron	
  crystals	
  containing	
  less	  than	
  athousand	
  molecules.
• Demonstrated	
  using	  Photosystem	
  I,	
  a
membrane	
  protein,	
  key	
  tophotosynthesis,	  	
  that	  is	
  extremely
diﬃcult	
  to	
  grow	
  into	  large	
  crystals.

Single-­‐shot	
  diﬀrac7on	
  pa?erns	
  are	  recorded
with	
  70	
  fs	
  pulses.	
  	
  Coherent	
  diﬀrac7onshows	  the	
  crystal	
  size	  is	
  sub-­‐micron	
  (top	  leF)and	
  that	  the	
  crystal	  has	  a	
  perfect	
  laHce.
Individual	
  shots	
  are	  oriented	
  in	
  3D	
  and
combined	  to	
  build	
  up	
  the	
  full	  informa7on
content	
  of	
  the	
  underlying	
  macromolecule(top	
  right).	
  	
  This	  ﬁrst	  demonstra7on	
  wascarried	
  out	  at	
  2	  keV	
  photon	  energy,	
  limi7ng
the	
  resolu7on	
  to	
  about	
  9	
  Å.	
  	
  (This	
  will	  beimproved	
  with	  the	
  dedicated	
  CXI
instrument.)	
  	
  The	
  quality	
  of	
  the	
  data	  aredemonstrated	
  by	
  carrying	
  out	
  molecularreplacement	
  reﬁnement	
  (right).	
  	
  Structuraldetails	
  such	  as	
  helices	
  can	  be	
  observed.

Linac Coherent Light Source• 30	
  single-­‐crystal	
  pa`erns	
  per	
  secondwere	
  recorded	
  from	  a	
  liquid	
  stream
carrying	
  a	
  suspension	
  of	
  nanocrystals.
15,000	
  of	
  these	
  were	  indexed	
  andcombined	
  into	
  a	
  full	  diﬀracIon	
  pa`ernwhich	  was	
  analyzed	
  with	  standard	
  tools.
• Data	  are	  collected	
  at	
  room	  temperature.
No	
  cryogenic	
  cooling	  or	
  stabilizaIon
required.

H.N. Chapman et al., Nature 470, 73 (2011)D.	
  Wang	
  et	
  al.,	
  S cience	
  3 24,	
  5931	
  (2009)	
  •Femtosecond electronic response of atoms toultraintense x-rays
Understanding	
  the	  response	
  of	
  ma?er	  to	
  ultraintense	
  x-­‐ray	
  irradia7on	
  is	
  vital	  for	
  LCLS	  applica7ons• LCLS	  provides	
  x-­‐ray	
  pulses	
  with	  peak	  intensiIes	
  more	  than	  abillion	  Imes	  greater	
  than	
  those	  from	  any	
  exisIng
synchrotron	
  source.	
  	
  Understanding	
  the	
  electronic	
  responseat	
  extreme	
  x-­‐ray	
  intensiIes	
  is	
  fundamental.
• By	
  studying	
  a	
  simple	
  target,	
  neon,	
  where	
  the	
  dominantinteracIon	
  changes	
  as	
  a	
  funcIon	
  of	
  photon	  energy	
  fromouter-­‐	  to	
  inner-­‐shell	
  absorpIon,	
  a	
  general	
  understanding
can	
  be	
  achieved.

Mul7photon	
  ioniza7on	
  of	
  atoms	
  occurs	
  within	
  a	
  single	
  LCLS
pulse	  of	
  ~100	
  fs	
  dura7on	
  and	
  ﬂuence	
  of	
  ~1012	  x-­‐rays	
  per	
  squaremicron.	
  The	
  mul7ple	
  ioniza7on	
  proceeds	
  through	  a	
  sequence	
  ofsingle	  electron	
  ejec7ons.	
  	
  Three	  types	
  of	
  electrons	
  are	
  ejected,
valence	
  (V),	
  inner-­‐shell	
  (P)	
  and	
  Auger	
  (A),as	
  depicted	
  on	
  the	  leFof	
  the	  diagram.	
  	
  One	
  can	  control	
  the	
  ioniza7on	
  mechanism.
Studying	
  the	
  prototypical	
  neon	
  atom:	
  at	
  photon	  energies	
  belowthe	
  K-­‐edge	
  (870	  eV)	  	
  the	
  outer	  electrons	
  are	
  stripped	
  (VVV…
process),	
  whereas	
  at	
  photon	  energies	
  above	
  the	
  K-­‐edge	
  theinner	
  electrons	
  are	
  ini7ally	
  ejected,	
  followed	
  by	
  femtosecond
Auger	
  decay	  	
  (PAPA…	
  process).	
  	
  	
  At	
  very	  high	  intensity,	
  both	  1score	
  electrons	
  can	  be	
  removed	
  prior	  to	
  reﬁlling	
  by	
  Auger	
  decayto	
  produce	
  exo7c	
  hollow	
  atoms.

• Observe	
  full	  stripping	
  of	
  neon	
  via	  a	
  six-­‐photon,	
  ten-­‐electron
process	
  within	
  a	
  single	
  ~100	
  fs	
  x-­‐ray	
  pulse	  –	
  the	
  ﬁrstobserved	
  mulIphoton	
  x-­‐ray	
  process.
• Observe	
  x-­‐ray	
  induced	
  transparency	
  via	
  hollow	
  atomformaIon	
  at	
  high	  x-­‐ray	
  intensiIes	
  –	
  predict	
  thisphenomenon	
  will	  be	
  generally	
  observed	
  in	
  molecules,	
  solids–	  allowing	
  one	  to	
  control	
  the	
  penetraIon	
  depth	  in	
  ma`erwith	
  pulse	
  duraIon.
• Straighdorward	
  rate	  equaIon	
  model	  reproduces	  theobserved	
  trends	
  –	
  suggesIng	
  that	  more	  complex	
  systems
may	
  be	
  modeled.

L. Young et al., Nature 466, 56 (2010)D.	
  Wang	
  et	
  al.,	
  S cience	
  3 24,	
  5931	
  (2009)	
  •- Focusing LCLS pulses of 960 eV into a Neon gas sample to a spot
size of ~1.5 mm, a long narrow plasma column is produced on a
femtosecond timescale by photoionization of the K-shell, resulting ina population inversion of the Ne K-a transition.
- Fluorescence photons of the front-end of the plasma column get
amplified by stimulated emission, resulting in ultrabright, fs x-ray
pulses at 850 eVSingle shot spectra of the transmitted LCLS line ataround 960 eV and the Ne K-a line at 850 eV (1.9 eV
instrument-limited width). The brightest shot
resulted in 2x109 photons in the Ne K-a line, with aconversion efficiency of 10-3.

Peak intensity of the Ne K-a line as a function of
the pumping power of the LCLS. Doubling thepumping intensity gives a rise in the peak power offour orders of magnitude.

- The photoionization-based atomic x-ray lasing scheme was
first proposed in 1967 (Duguay and Renzepis)- Due to requirement of an extremely fast and intense xray pump source, it could never be realized so far.
- The experiment is a first step in the virtually unexplored
field of non-linear quantum optics with x-rays and opens thepathway to new, non-linear spectroscopic methods in the xray regime
N. Rohringer et al., manuscript in preparation
Linac Coherent Light SourceControlling magnetism in complex oxide with lattice excitation
New approach for magnetic switching disclosed at the LCLS Free Electron Laser• To date, light control of magnetization has always been
induced by near-infrared light. This type of stimulation isassociated with large dissipation, as eV-photon energies areused to drive the rearrangement of the microscopic order on
the meV energy scale.
• Electronic properties of complex oxides can be controlled by
optical excitation of lattice vibrations in the mid infrared,
providing an alternate path to steer condensed matter onultrafast timescales.
• Recent experiments at the LCLS Free Electron Laser utilizingtime-resolved resonant soft X-ray diffraction demonstrate thatthe magnetic order in complex oxides can be disorderedthrough optical lattice manipulation.
Mid-infrared laser light shakes the crystal lattice of thelayered manganite La0.5Sr1.5MnO4 through resonant
excitation of a vibrational mode. Antiferromagnetic order
is in this way perturbed, as viewed by time-resolved
resonant soft X-ray diffraction from the magnetic
superlattice.

Linac Coherent Light Source• The magnetic response time is 12ps, likely dictated by spinlattice relaxation rates.

M. Först, R.I. Tobey, S. Wall et al., to be publishedLCLS pump-probe experiments: CO on Ru(001)•	  Nearly	
  all	
  chemical	
  reacIons	
  of	
  importanceto	
  society	
  occur	
  at	
  interfaces•	  Catalysis	
  is	
  a	
  trillion	
  dollar	
  industry	
  and	
  is
also	
  at	
  the	
  core	  of	
  chemical	
  energytransformaIons•	
  	
  The	
  ﬁrst	  pump	
  probe	
  experiment	
  at	
  LCLS
invesIgated	
  a	
  simple	  reacIon	
  step	  involving
breaking	
  of	
  the	
  CO-­‐metal	
  bond•	
  The	
  experiments	
  use	  a	  400	  nm	  opIcal	
  laserpump	
  pulse,	  and	  a	  LCLS	
  pulses	
  to	
  probe	  theCO	
  electronic	
  structure	
  state	  though	  O	
  K-­‐
emission	
  spectroscopy	
  as	
  a	
  funcIon	
  of	
  Ime
delay.
•	  The	  results	
  shows	
  the	
  Ime	
  evoluIon	
  of	
  a
transient	
  CO	
  state	
  where	
  the	
  chemical	
  bondstrength	
  to	
  the	
  surface	
  is	
  reduced
PIs: Anders Nilsson, Hirohito Ogasawara, Dennis Nordlund (SLAC), Wilfried Wurth (DESY), Alexander Föhlish (Helmholtz center), HenrikÖström (Sockholm U) and Martin Wolf (Fritz Haber Institute)
Linac	
  Coherent	
  Light	
  Source

Conclusion

Much of the most exciting recent science
with Neutrons and X-rays has resulted fromfruitful collaborations between
accelerator physicists and CM andMaterials Scientists
and Crystallographers and Biologists
Hopefully, this will continue, leading to more
exciting science over the next decade,So, this is not……………..

THE END