“ 放射光を利用した物性科学の発展と展望” 研究会...

“ 放射光を利用した物性科学の発展と展望” 研究会原研放射光科学研究センター、 2004 年 3 月 18-19 日　

藤森　淳（東大新領域、原研放射光）

f f 電子系超伝導体の軟電子系超伝導体の軟 XX 線放射光分光線放射光分光

共同研究者藤森伸一、斎藤祐児、岡根哲夫、岡本淳、中谷健、村松康司（原研放射光）間宮一敏（ KEK － PF ）島田賢也、成村孝正、小林賢一、生天目博文、谷口雅樹（広島大放射光）池田修悟、青木大、宍戸寛明（阪大理）芳賀芳範、山本悦嗣、松田達麿（原研先端研）大貫惇睦（阪大理、原研先端研）山上浩志、常盤欣文（京都産業大）、播磨尚朝（阪大産研）田中新（広島大先端物質）

• JAERI beamline BL-23SU– PES– MCD

• Ce and U exotic superconductors– Ce115 compounds: superconductivity near QCP

• U115 compounds

– Ferromagnetic superconductor UGe2

– Antiferromagnetic superconductor UPd2Al3

OutlineOutline

Beamlines in Spring-8 Beamlines in Spring-8

RI samples(U compounds)

cylindrical mirror

177°

top view

cylindrical mirror

toroidal mirrorgrating exit slitspherical mirror

spherical mirror 177°entrance slit177°

cylindrical mirror

VLSPGG1: 1000 lines/mmG2: 600 lines/mm

4250040000

71910

2500

61338

73910 114000

61910

10955

955

75000

50000 60955

10000

0

Mh

179°side view

M3APPLE-2

M1 M2

S1 S2177° 176°174°

175°

Mv

M4ST1 ST2 ST3

u=12cm

N=16

0 10 20 30 5040 60 70 80 90 100 110 120 130 140

Distance to source point (m)

MhMv

variably-polarizing undulator

monochromator

biological application

station

beam-transport pipe

entrance slit

M1,M2

VLSPG

exit slit

M3 M4

RI inspection port 2

surface photo- chemistry station

fluorescence screen

RI inspection port 3

radiation detector

acitinide science station

beam monitor

cryopump system

fast closing gate valve



experimental hallHot Sample Area

hutch for optics

beam shutter

XYslit

absorber

front end

fixed mask

beam position monitor


-stopper

XY slit

fluorescence screen


u=12cm Np=16

(Hettrick-Underwood type)

200 500 1000 1500 2000

photon energy (eV)

174° G2

176° G2

176° G1

Y. Saitoh et al., Nucl. Instrum. Methods A ’01.

JAERI beamline BL-23SU of Spring-8JAERI beamline BL-23SU of Spring-8

Y. Saitoh et al., Rev. Sci. Instrum. ’ 00


MCD 装置

ARPES 装置

PES station 　　 Scienta 2002, Gammadata VUV5000MCD station 　　 Superconducting magnet, up to 10 T　　 Low temperature, down to 10 KU compounds can be measured


0 10 20 30 5040 60 70 80 90 100 110 120 130 140

Distance to source point (m)

MhMv

variably-polarizing undulator

monochromator

biological application

station

beam-transport pipe

entrance slit

M1,M2

VLSPG

exit slit

M3 M4


surface photo- chemistry station


RI inspection port 3

radiation detector

acitinide science station

beam monitor

cryopump system




experimental hallHot Sample Area

hutch for optics

beam shutter

XYslit

absorber

front end

fixed mask

beam position monitor


-stopper

XY slit

fluorescence screen


u=12cm Np=16

(Hettrick-Underwood type)

MCD　

PES　

Synchrotron Radiation

Resonant photoemissionResonant photoemission

S.I. Fujimori et al

A. Sekiyama et al., Nature ‘00. K. Shimada et al.

Resonant photoemissionResonant photoemission

Angle-resolved photoemission (ARPES)Angle-resolved photoemission (ARPES)

A1 - A2

MCD in core-level x-ray absorption MCD in core-level x-ray absorption from metal 2from metal 2pp core level core level

spin sum rule

orbital sum ruleElement-selective magnetic probe

　　 Superconducting magnet, up to 10 T　　 Low temperature, down to 10 K

Apple II-type helical undulator



• U115 compounds



OutlineOutline

Superconductivity near quantum critical pointSuperconductivity near quantum critical point

S. DoniachG.G. Lonzarich

Antferromagnetic metal Fermi liquid

Non-Fermi liquid

superconducting

quantum critical point

Doniach’s phase diagram

Quasi-2D superconductors near Quasi-2D superconductors near quantum critical point Cequantum critical point CeTTInIn5 5 ((TT=Rh, Ir, Co)=Rh, Ir, Co)

H. Hegger et al. PRL ‘00H. Shishido et al. PRB ‘02

Ce

In

Rh, Ir

Superconductivity at ambient pressure in CeIrIn5 (TC = 0.4 K) and CeCoIn5 (TC = 2.2 K)

supercond.

antiferromagnetic

S. DoniachG.G. Lonzarich

Antferromagnetic metal Fermi liquid

Non-Fermi liquid

superconducting

quantum critical point

CeRhIn5 CeIrIn5

CeCoIn5

Doniach’s phase diagram

pressure

H. Shishido et al. JPSJ 02

Quasi-2D superconductors near Quasi-2D superconductors near quantum critical point Cequantum critical point CeTTInIn5 5 ((TT=Rh, Ir, Co)=Rh, Ir, Co)

S.I. Fujimori et al., PRB ‘03S.I. Fujimori et al., Physica C ‘03

Resonant photoemission and XASResonant photoemission and XAS

Ce 4d-4fCe 3d-4f

Ce 3d XAS

nf ~ 1

@ Hi-SOR

spin-orbit sideband

@ Spring-8

CeRhInCeRhIn55: AREPS and band-structure calculations: AREPS and band-structure calculations

S.I. Fujimori et al., PRB ‘03Band calc: H. Harima

h = 21.2 eV

CeIrInCeIrIn55: AREPS and band-structure calculations: AREPS and band-structure calculations

h = 21.2 eV

S.I. Fujimori et al., PRB ‘03Band calc: H. Harima

A

M

ARPES Fermi surfaces in CeIrInARPES Fermi surfaces in CeIrIn55

H. Harima

Fermi surface mappingcompared with LDA

Fermi surface of CeIrIn5 by LDA calculation

S.I. Fujimori et al., PRB ‘03

Wf

Hybridized Hybridized spdspd--ff band model band model

f band

Ce compound La compound

spd band

Hybridized Hybridized spdspd-Ce 4-Ce 4ff bands in CeIrIn bands in CeIrIn55

S.I. Fujimori et al.

4d-4f RPES (h = 122 eV) → Ce 4f 　

@ Hi-SOR

He I (h = 21.2 eV) → sp



• U115 compounds



OutlineOutline

Quasi-2D UQuasi-2D UTTGaGa55 ( (T T = Fe, Pt)= Fe, Pt)

U

Ga

Fe, Pt

UFeGa5 : paramagentUPtGa5 : antiferromagnet (T Ｎ =26K)

cf) PuCoGa5: superconductor (TC=18.5K)

UTGa5 U

Fe, Pt

Ga

UGa3

Photoemission spectra of UPhotoemission spectra of UTTGaGa55 ( (T T = Fe, Pt)= Fe, Pt)


U 5fsensitivity

Fe 3d U 5fU 5f

AFMPM

S.I. Fujimori et al.Band calc: H. Yamagami

Band structure and Fermi surfaces of UFeGaBand structure and Fermi surfaces of UFeGa55

wide 5wide 5ff band band

Fermi surface mapping

Photoemission spectra of UPhotoemission spectra of UTTGaGa55 ( (T T = Fe, Pt)= Fe, Pt)


U 5fsensitivity

Fe 3d U 5fU 5f

AFMPM


Band structure of UPtGaBand structure of UPtGa5 5

narrow 5narrow 5ff band band



• U115 compounds



OutlineOutline

Ferromagentic superconductor UGeFerromagentic superconductor UGe22

S. S. Saxena et al., Nature ‘00A. Huxley et al., PRB ‘01N. Tateiwa et al., JPSJ ‘01

ferromagnetic

supercond.

TCurie = 52 K TSC = 0.8 [email protected] GPaT* ~ 30 K: anomaly ?

T*

T*

TCurie

new order parameter ?

U U MM4,54,5 (3 (3dd 5 5ff) MCD of U compounds ) MCD of U compounds

S.P. Collins et al., J. Phys. Cond. Mat. ‘95

Raw data (TFY method)

Corrected data

self-absorption effects

matrix-element effects ??

US

-1.46-1.522.98LDA

-2.24-1.172.62U3+diffraction-2.60-0.912.37U4+Neutron

-1.9-1.52.9MCD (T=25K)

L/SSL

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

42 K

36 K

33 K

30 K

25 K

U N4,5 XAS

N5N4

-0.15

-0.10

-0.05

0.00

840820800780760740720700

Photon Energy (eV)

U N4,5 MCD

42 K 36 K 33 K 30 K 25 K

1.0

0.8

0.6

0.4

0.2

0.0840800760720

T = 25 K

T. Okane et al.Neutron: Keranvanois et al., PRB ‘01

U U NN4,54,5 (4 (4dd 5 5ff) MCD of UGe) MCD of UGe22

1120108010401000photon energy (eV)

MCD

1.0

0.5

0.0

UGe2

U N3 XAS

0.04

0.02

0.00

-0.02

-0.04

U U NN33 (4 (4pp 6 6dd), Ge ), Ge LL2,32,3 (2 (2pp 4 4ss)) MCD of UGeMCD of UGe22

T. Okane et al.

No polarization of U 6d electrons

Finite Ge L2,3 MCD Finite polarization of Ge 4s electrons

-1.46-1.522.98LDA

-2.24-1.172.62U3+diffraction-2.60-0.912.37U4+Neutron

-1.9-1.52.9MCD (T=25K)

L/SSL

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

42 K

36 K

33 K

30 K

25 K

U N4,5 XAS

N5N4

-0.15

-0.10

-0.05

0.00

840820800780760740720700

Photon Energy (eV)

U N4,5 MCD

42 K 36 K 33 K 30 K 25 K

1.0

0.8

0.6

0.4

0.2

0.0840800760720

T = 25 K

T. Okane et al.Neutron: Keranvanois et al., PRB ‘01

U U NN4,54,5 (4 (4dd 5 5ff) MCD of UGe) MCD of UGe22

3.0

2.5

2.0

1.5

1.0

0.5

0.05040302010

Temperature (K)

-3.0

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

tot L S

U U NN4,54,5 MCD of UGe MCD of UGe2 2 : Temperature dependence : Temperature dependence

T. Okane et al.

T* TCurie



• U115 compounds



OutlineOutline

localized itinerant

U 5f electrons

UPt3

a = 5.764 Åc = 4.899 Å

TN= 5 K(0.02B)TC= 0.4 K

UPd2Al3

a = 5.382 Åc = 4.189 Å

TN= 14K(0.85B)TC= 2 K

UNi2Al3

a = 5.027 Åc = 4.018 Å

TN= 2.4K(0.24B)TC= 1 K

Antiferromagentic superconductors Antiferromagentic superconductors

Photoemission spectra of UPdPhotoemission spectra of UPd22AlAl33


• Ce115 compounds: superconductivity near QCP– Ce 4f electrons are nearly localized, nf ~ 1.

– but participates in band/Fermi surface formation in CeIrIn5.

• U115 compounds – Different degrees of localization have been demonstrate

d between UFeGa5 and UPtGa5.

• Ferromagnetic superconductor UGe2 – Spin and orbital moments and their temperature depend

ence have been obtained by MCD

– with no anomaly at ~T*

ConclusionsConclusions

• High (optimized) beamline performance has been achieved at BL-23SU.– Many scientific opportunities are foreseen.

• U compounds– SX-AREPS, MCD, core-level XPS

• Basic sciences of strong correlation– 3-dimensional transition-metal oxides -- SX-ARPES– Ferromagnetic oxides -- MCD

• Nano-sciences– Diluted magnetic semiconductors -- MCD at low-T, high-H– Oxide thin films, interfaces, nano-structures– Intercalation, nano-magnets, …..

Scientific opportunities at BL-23SUScientific opportunities at BL-23SU

PLD

SR

PES

CCD Cameras

Combined Combined in situin situ PES-PLD system PES-PLD system

cf. Oshima group at KEK-PF

• U compounds– SX-AREPS, MCD, core-level XPS

• Basic sciences of strong correlation– 3-dimensional transition-metal oxides -- SX-ARPES– Ferromagnetic oxides -- MCD

• Nano-sciences– Diluted magnetic semiconductors -- MCD at low-T, high-H– Oxide thin films, interfaces, nano-structures– Intercalation, nano-magnets, …..

Scientific opportunities at BL-23SUScientific opportunities at BL-23SU

• New directions: Proposals are welcome !

原研放射光・電子物性研究グループ原研放射光・電子物性研究グループ

■ 研究テーマ " 強相関電子系機能性材料の電子構造に関する研究 "超伝導や巨大磁気抵抗など特異な物性を示す遷移金属、希土類、ウランを含む強相関電子系物質とこれらの物質を複合化、ナノ構造化した新しい機能を持つ物質・材料の化学結合状態・電子構造を各種軟 x 線分光法を用いて明らかにする。得られた情報から物質設計・材料設計の指針を得て IT 、環境、エネルギーに関連した新材料の開発に資する。

■ メンバー安居院あかね / Akane Agui岡根哲夫 / Tetsuo Okane岡本淳 / Jun Okamoto　　博士研究員斉藤祐児 / Yuji Saitoh竹田幸治 / Yukiharu Takeda　　博士研究員竹山雅義 / Masayoshi Takeyama 　業務協力員寺井恒太 / Kota Terai　　博士研究員中谷健 / Takeshi Nakatani藤森淳 / Atsushi Fujimori　　客員研究員藤森伸一 / Shinichi Fujimori村松康司 / Yasuji Muramatsu　　グループリーダー

http://jaeriwww.spring8.or.jp/~denshi/member/JOkamoto/JOkamoto.html

http://jaeriwww.spring8.or.jp/~denshi/member/JOkamoto/JOkamoto.html

http://jaeriwww.spring8.or.jp/~denshi/member/YTakeda/YTakeda.html



http://jaeriwww.spring8.or.jp/~denshi/member/KTerai/KTerai.html



“ 放射光を利用した物性科学の発展と展望” 研究会...

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