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1/28 The studies of electronic structure of The studies of electronic structure of strongly correlated materials by the strongly correlated materials by the combination of HAXPES and other combination of HAXPES and other techniques techniques Munetaka TAGUCHI Munetaka TAGUCHI ( ( RIKEN/SPring RIKEN/SPring - - 8, Excited Order Research team 8, Excited Order Research team ) ) HAXPES2009 20-22/May/2009
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The studies of electronic structure of The studies of electronic structure of strongly correlated materials by the strongly correlated materials by the combination of HAXPES and other combination of HAXPES and other
techniquestechniques
Munetaka TAGUCHIMunetaka TAGUCHI((RIKEN/SPringRIKEN/SPring--8, Excited Order Research team8, Excited Order Research team))
HAXPES200920-22/May/2009
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ContentsContents
Introduction
NiO
Magnéli phaseTi4 O7
Summary
Introduction
NiO
Magnéli phaseTi4 O7
Summary
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La1-x Srx MnO3 V1.98 Cr0.02 O3 High Tc cuprates
Horiba et al., PRL 93 236401 (2004)
Taguchi et al., PRB 71 155102 (2005)
Kamakura et al.,EPL 68 557 (2004)
Taguchi et al., PRL 95 177002 (2005)
IntroductionIntroduction
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Mo et al. PRL 90, 186403 (2003)Zhang et al. PRL 70, 1666 (1993)Panaccione et al. PRL 97 116401 (2006)Fujimori’s Lecture note
Coherent part
Incoherent part
U
DMFT cal.
VB-PES : V2 O3
Coherent peak in VBCoherent peak in VB--PESPES
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EF
O 2p band
3d
Central V atom
Coherent band
Neighboring site１．Intra-atomic multiplet
３．Hybridization betweenO 2p and V 3d orbital
２．Crystal Fields (C3v )
４．Screening from coherent bands
V
V*
ConfigurationConfiguration--interaction (CI) model interaction (CI) model
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Ground state：linear combination of 6 configurations
3d2 3d4L2
3d4LC
3d3L
3d3C
3d4C2
ParametersΔ= 6.0 eVU
= 4.5 eVUdc
= 6.5 eV10Dq
= 1.2 eVDtrg = - 0.05 eVV
= 2.9 eVV *
= 0.75 eVΔ* = 0.9 eVRc =0.8, Rv=0.9
U EF
O 2p band
UH
LH
CI modelCI model
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Taguchi et al.PRB 71, 155102 (2005)
*-Udc |
2p53d 2-Udc |
*
3d3L
3d3C
3d 2
2p53d3L
2p53d3C
|
f ›|
g ›
Calculation vs. Experiment Calculation vs. Experiment
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Introduction
NiO
Magnéli phaseTi4 O7
Summary
ContentsContents
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Van Veenendaal et al., PRL 70 2459 (1993)
2p53d9Lnon-local
multi-site cluster model
Ni 2p3/2 core level
NonNon--local screening local screening
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spin-fermion model: Bala et al., PRL 72 2600 (1994): PRB 61 13573 (2000)
LDA+DMFT: Ren et al., PRB 74 195114 (2006)Kunes et al., PRB 75 165115 (2007): PRL 99 156404 (2007)
Zhan-Rice doublet bound states
ZhangZhang--Rice doublet bound stateRice doublet bound state
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Parmigiani et al., J. Electr. Spectr. Rel. Phen. 98-99 287(1999)
Taguchi et al., PRL 100 206401 (2008)
A
BC
Ni 2p HXNi 2p HX--PESPES
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EF
O2p band
3d
Central Ni atom
ZR doubletbound state
2p core2p core--level HXlevel HX--PESPES
13/28Experiments: BL17SU @ SPring-8
Valence band PESValence band PES
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without 3d9Z
with 3d9Z
Experiments: BL17SU @ SPring-8
Resonant PES at Resonant PES at LL33
edgeedge
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Introduction
NiO
Magnéli phaseTi4 O7
Summary
ContentsContents
16/27T. Tonogai（PhD thesis）
4.0
3.5
3.0Valence
Metal
Insulator
Intermediatephase
MagnMagnééli phase: Tili phase: Ti44 OO77
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Abbate et al.,PRB51, 10150 (1995).
h = 45 eV
Kobayashi et al., Europhys. Lett. 59, 868 (2002).
Previous resultsPrevious results
extremely broad featuresextremely broad features
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Clear FermiClear Fermi--edgeedge
Metal Phase:Metal Phase:FermiFermi--Liquid stateLiquid state
Ti 2p resonant PESTi 2p resonant PES
Taguchi et al., cond-mat/0902.3701
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GaussianFermi-DiracSpectral function
Laser PESLaser PES
Taguchi et al., cond-mat/0902.3701
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mobile carriermobile carrier：：nn--typetype
Seebeck coefficient
O 1sconduction
band
LT
HT
IT
PESXAS
XASPES
PESXAS
EF
O 1s XAS & O 1s HXO 1s XAS & O 1s HX--PESPES
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O 1s
gap
conductionband
LT
HT
IT
valence band
PESXAS
XASPES
PESXAS
EF
Schematic picture Schematic picture
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Ti 2p HXTi 2p HX--PESPES
Taguchi et al., cond-mat/0902.3701
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*-Udc
|
2p53d0
-Udc
|
*
3d1L
3d1C
3d0
2p53d1L
2p53d1C
CT| g
› | f
›
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Ti4+ cluster（V* =0）
Ti 3+
Ti3+Ti4+
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ParametersΔ* = 0.3 eV
V
* = 0.26 eV
Ti4+ cluster
Ti 3+
coherent nature coherent nature
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NiO: All features in the VB and the core-level PES were reproduced well by extended CI model including ZR bound state screening effects.
Ti4 O7 : Resonant PES …. Fermi liquid state in HT phaseLaser PES …. Pseudo-gap feature in IT Ti 2p HX-PES …. This pseudo-gap feature is associated
with the coherent screening states.
SummarySummary
Further information on the nature of electronic state near EF can be obtained from the combination of HX-PES and other techniques.
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S. ShinA. ChainaniY. TakataY. IshidaT. Takeuchi
RIKEN/SPring-8Soft x-ray Lab.
T. IshikawaM. YabashiK. TamasakuY. Nishino
RIKEN/SPring-8Coherent x-ray Optics Lab.
NIMS S. Tsuda
Univ. of Tokyo
H. TakagiM. FujiwaraY. Nakamura
JASRI H. OhashiY. Senba
ISSPR. EguchiM. MatsunamiS. Watanabe
AcknowledgementsAcknowledgements
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Thank You very much for your attentionThank You very much for your attention
