SOLID STATE SPECTROSCOPY SUMMER TERM 2014 Prof. Dr. Bernhard
Keimer [email protected] Dr. Mathieu Le Tacon [email protected]
07/04/2014Solid State Spectroscopy - Introduction1
http://www.fkf.mpg.de/1786169/Teaching Slide 2 Solid State
Spectroscopy - Introduction2 Objective of this lecture Provide a
general background on some of the experimental spectroscopic
techniques that are most commonly used to study materials Provide a
general background on some of the experimental spectroscopic
techniques that are most commonly used to study materials -Optical
Spectroscopy (absorption/reflectivity/ellipsometry) -Inelastic
light scattering (Raman, Inelastic X-ray Scattering) -X-ray
absorption Spectroscopy (XAS) -Nuclear Magnetic Resonance (NMR)
-Inelastic Neutron Scattering (INS) -Tunneling Spectroscopy
(STM/STS) -Angle Resolved Photoemission Spectroscopy (ARPES) etc
-Optical Spectroscopy (absorption/reflectivity/ellipsometry)
-Inelastic light scattering (Raman, Inelastic X-ray Scattering)
-X-ray absorption Spectroscopy (XAS) -Nuclear Magnetic Resonance
(NMR) -Inelastic Neutron Scattering (INS) -Tunneling Spectroscopy
(STM/STS) -Angle Resolved Photoemission Spectroscopy (ARPES) etc
Slide 3 07/04/2014Solid State Spectroscopy - Introduction3
Non-exhaustive bibliography Slide 4 SOLID STATE 07/04/2014Solid
State Spectroscopy - Introduction4 Material Science Technological
applications New materials: synthesis/design Original Physical
Properties Nature 410, 63 (2001) 2006 2014 MgB 2
www.columbussuperconductors.com
http://www.nanowerk.com/news2/green/newsid=34722.php Slide 5 SOLID
STATE 07/04/2014Solid State Spectroscopy - Introduction5 Material
Science Technological applications New materials: synthesis/design
Original Physical Properties Slide 6 07/04/2014Solid State
Spectroscopy - Introduction6 Materials for the future ? Graphene
Transition metal oxide superlattices BUT prior to application need
to understand fundamental properties
http://cdn.phys.org/newman/gfx/news/hires/ 2012/1-interfacesar.jpg
http://upload.wikimedia.org/wikipedia/comm ons/9/9e/Graphen.jpg
Slide 7 Spectroscopy ? 07/04/2014Solid State Spectroscopy -
Introduction7
http://www.astroclubmarsan.net/nvxsite/atelierspectro.htm Slide 8
From the atomic building block 07/04/2014Solid State Spectroscopy -
Introduction8 Weakly coupled spectator (NMR) -Nucleus : charge Ze +
mass spin I ( magnetic moment M I = -g N I ) -Nucleus : charge Ze +
mass spin I ( magnetic moment M I = -g N I ) -Electrons : charge e
spin S ( magnetic moment M S = -g B S ) -Electrons : charge e spin
S ( magnetic moment M S = -g B S ) Slide 9 to the solid
07/04/2014Solid State Spectroscopy - Introduction9 Nuclei: -
Lattice structure - Local defects Nuclei: - Lattice structure -
Local defects Charge: - Band structure ? - electronic structure of
the defects Charge: - Band structure ? - electronic structure of
the defects Spin: - Magnetic structure (e.g. ferro-/
anti-ferromagnetic) Spin: - Magnetic structure (e.g. ferro-/
anti-ferromagnetic) STATIC PROPERTIES (GROUND STATE) Slide 10 to
the solid 07/04/2014Solid State Spectroscopy - Introduction10
Nuclei: - individual: diffusion - Collective: phonons Nuclei: -
individual: diffusion - Collective: phonons Charge: - Individual
(Intra/Interband, Exciton) - Collective (plasmon) - topological
(Vortex) Charge: - Individual (Intra/Interband, Exciton) -
Collective (plasmon) - topological (Vortex) Spin: - individual:
single spin flip - collective: spin waves/magnons - topological:
skyrmions Spin: - individual: single spin flip - collective: spin
waves/magnons - topological: skyrmions DYNAMIC PROPERTIES
(EXCITATIONS) Microscopic origin of THERMODYNAMIC Properties !
Slide 11 07/04/2014 Solid State Spectroscopy - Introduction11
Crystal/Magnetic Structure x-ray /Neutrons/NMR What Experimental
techniques ? MgB 2 Dynamical properties Charge electrodynamics:
optics Phonon (lattice vibrations): optics, Raman, INS, IXS.
Shukla, et al. PRL 90, 095506 (2003) Electronic Structure ARPES STM
XAS Ab-initio calculation Souma et al. Nature 423 65(2003) Kortus
et al.PRL 86 4656(2003) Slide 12 Experimental Method probe
Interesting system InteractionResponse Solid State Spectroscopy -
Introduction12 Linear response framework: Response = Susceptibility
x Perturbation Linear response framework: Response = Susceptibility
x Perturbation Intrinsic property of the system Slide 13 Linear
Response Theory Assume in the absence of perturbation Consider an
observable(Magnetization, Current, Scattering Cross-section etc..)
Consider a external perturbation (=weak) Assuming system
homogeneity and time translation invariance It is often more
convenient (and relevant) to work directly with Fourier transform
Solid State Spectroscopy - Introduction13 Important :is directly
related to correlation functions Slide 14 The Probes (pertubations)
Solid State Spectroscopy - Introduction14 1) Electro-magnetic field
2) Particles Particleelectronpositronsmuonsneutronsproton Mass m e
=9,1 10 -31 kg m p =9,1 10 -31 kg m =1,88 10 -28 kg M N =1,675 10
-27 kg M P =1,673 10 -27 kg Z.M P + (A-Z).M N -E B /c 2 ~Z.M P +
(A-Z).M N -E B /c 2 Charge-e+e-e0+e+Ze ne Spin1/2 0 if Z and A are
even S > 1/2 for 75% of isotopes Depends on n ( e >>
Nucleus ) (Internal probe) Slide 15 PerturbationResponding
Observable ? Associated Susceptibility corresponding Correlations
Magnetic Field H Magnetization M Magnetic Susceptibility m
Spin-spin (static/uniform) Spin of NeutronsMagnetic Scattering
Cross section S(q, ) Magnetic Susceptibility m (q, ) Spin-spin
(non-uniform) Electric Field E Polarization PCharge Susceptibility
(q=0, ) Charge-charge (static/uniform) Electric Field E Electrical
current jElectrical conductivity q=0, Current-current (uniform)
Electric Field E (x-ray beam) Scattering Cross section S(q, )
Charge Susceptibility (q, ) Charge-charge (non-uniform) NMR/ESR/ SR
Neutron Scattering Raman Optics X-ray scattering Solid State
Spectroscopy - Introduction15 Slide 16 Experimental techniques:
absorption Interesting system Ground State Incident photon Excited
State Solid State Spectroscopy - Introduction16 e.g. NMR B = 0 B 0
I Z = -1/2 I Z = 1/2 E ~ n B loc with n ~ few 10 MHz B loc : local
field at the nucleus position Includes surrounding e- through
hyperfine coupling e.g. light absorption (dipolar selection rules J
= 0, 1) Kortus et al.PRL 86 4656(2003) Slide 17 Experimental
techniques: Luminescence Interesting system Ground State Incident
stimulus (photon/electron) Excited State Solid State Spectroscopy -
Introduction17 Emitted photon Slide 18 Experimental techniques:
Photo-emission Interesting system Ground State Incident Photon
Excited State Solid State Spectroscopy - Introduction18
Photo-electron Moser et al. NJP 16 013008 (2013) Analysis of energy
and momentum of the photo-electron allows to map out the band
structure (here Ba 2 IrO 4 ) Slide 19 Experimental techniques:
Scattering Interesting system Ground State Incident Particule
(photon/electron/neutron) Excited State Solid State Spectroscopy -
Introduction19 Distinct from luminescence ! Scatterd Particule Can
be - elastic (without loss/gain of energy) e.g. Diffraction -
inelastic e.g. Raman scattering, inelastic neutron scattering (INS)
- coherent (e.g. diffraction) - incoherent (e.g. Compton
scattering) Can be - elastic (without loss/gain of energy) e.g.
Diffraction - inelastic e.g. Raman scattering, inelastic neutron
scattering (INS) - coherent (e.g. diffraction) - incoherent (e.g.
Compton scattering) Slide 20 The Probes Solid State Spectroscopy -
Introduction20 1) Electro-magnetic field Slide 21 Solid State
Spectroscopy - Introduction21 AbsorptionNMRESRIRPhotoemissionXAS
ScatteringRamandiffraction IXS/RIXS
http://www.itst.ucsb.edu/~vinhnguyen/VNAPIC/VDI-12.jpg Slide 22
Wavenumber Frequency Energy Temperature FrequencyEnergyTemperature
Appendix: the units Slide 23 Solid State Spectroscopy -
Introduction23 AbsorptionNMRESRIRPhotoemissionXAS
ScatteringRamandiffraction IXS/RIXS
http://www.itst.ucsb.edu/~vinhnguyen/VNAPIC/VDI-12.jpg Slide 24
Photon Sources to cover the entire spectral range Solid State
Spectroscopy - Introduction24 Slide 25 Blackbody radiation Solid
State Spectroscopy - Introduction25 Continuous source in the near
IR - visible range Limitation: Temperature W wire Slide 26 Lamps
Solid State Spectroscopy - Introduction26 Higher temperature
emitters: ionized plasma up to 6000 K: Visible Low pressure:
discrete spectral lines High pressure : continuum
http://www.olympusmicro.com/primer/lightandcolor/lightsourcesintro.html
http://www.photonics.com/images/Web/Articles/2010/10/8/HamamatsuFig1.jpg
Slide 27 L.A.S.E.R. (Light Amplification by Stimulated Emission of
Radiation) https://lasers.llnl.gov/ Solid State Spectroscopy -
Introduction27 Slide 28 L.A.S.E.R. (Light Amplification by
Stimulated Emission of Radiation) Solid State Spectroscopy -
Introduction28 1 2 and allow to retrieve Plancks law Equilibrium:
Slide 29 L.A.S.E.R. (Light Amplification by Stimulated Emission of
Radiation) Solid State Spectroscopy - Introduction29
en.wikipedia.org/wiki/Laser Slide 30 Solid State Spectroscopy -
Introduction30 So far IR-visible-UV sources: a few orders of
magnitude Photon carries energy AND momentum c = 299 792 458 m s -1
1 eV = 1.602 x 10 -19 J Solid in the real space a b a* b* Solid in
the reciprocal space Visible light only probes the center of the
reciprocal space ! Equivalently >> a No information at the
atomic scale All unit cells are in phase Slide 31 Brighter Photon
Sources: Synchrotrons Solid State Spectroscopy - Introduction31
Radiation of a relativistic accelerated charge
www.synchrotron-soleil.fr/ Slide 32 Brighter Photon Sources:
Synchrotrons Solid State Spectroscopy - Introduction32 Measuring
the quality of the photon source: Brilliance Size of the source
Beam angular divergence Slide 33 Solid State Spectroscopy -
Introduction33 X-ray tube 3 rd Generation synchrotron (soft) 3 rd
Generation synchrotron (hard) ESRF LCLS Free electron lasers 2 nd
Generation synchrotron NSLS Slide 34
http://www.veqter.co.uk/residual-stress-measurement/synchrotron-diffraction
A world of synchrotrons Solid State Spectroscopy -
Introduction34
