㕘⬎埻柀➇䞼䨞䛂䝁䞁䝢䝳䞊䝔䜱䜽䝇䛻䜘䜛≀㉁䝕䝄䜲䞁䠖」ྜ┦㛵䛸㠀ᖹ⾮䝎䜲䝘䝭䜽䝇䛃
2010ᖺ9᭶18᪥䠄ᅵ䠅10:30 – 17:30㻌 ᶡӜབྷᆖᐕᆖ䜘˒ਧ佘63ਧ䅋㗙ᇔ䝥䝻䝖䞁䚸䝭䝳䞊䜸䞁䛷᥈䜛᪂≀ᛶ䛸㔞Ꮚ䝎䜲䝘䝭䜽䝇◊✲௦⾲⪅ ୰すᐶ䠄኱㜰኱Ꮫ㻌 ᕤ䠅◊✲ศᢸ⪅ ୗྖ㞞❶䠄኱㜰኱Ꮫ䝘䝜䝉䠅ᚋ⸨ⱥ࿴䠄኱㜰኱Ꮫ㻌 ᕤ䠅Markus Wilde(ᮾி኱Ꮫ㻌 ⏕◊䠅Dino Wilson(኱㜰኱Ꮫ㻌 ᕤ䠅㐃ᦠ◊✲⪅ ⚟㇂ඞஅ(ᮾி኱Ꮫ㻌 ⏕◊)➟஭⚽᫂䠄኱㜰኱Ꮫ㻌 ᕤ䠅Particles in the system

Surface, Subsurface, Bulk, Interface

electron㻌e-9.1093897㽢10-31kg

1㻌 㻌 㻌
Hydrogen atom,
proton㻌 P䠇

HX 1836.14

1.00794

1.672210x10-27kg
Other atom

X 50䡚200ion core46㻌 㻌 㻌79㻌 㻌 㻌PdPt

106.42

195.07829㻌 㻌 㻌Cu63.536

Particles in the system

Surface, Subsurface, Bulk, Interface

electron㻌e-(Anti)Muon 㻌 μ䠇
1.9㽢10-28 kg

9.1093897㽢10-31kg

X 206.7

X 8.882
㻌 P䠇

proton1㻌 㻌 㻌

HX 1836.14

1.00794

1.672210x10-27kg
Other atomion core3㻌 㻌 㻌

Li
6.941

79㻌 㻌 㻌Pt
195.078

X 50䡚20046㻌 㻌 㻌Pd
106.4229㻌 㻌 㻌Cu63.536

䝥䝻䝖䞁䛾㔞Ꮚᛶ䠖䝥䝻䝖䞁䞉䝭䝳䞊䜸䞁⛉Ꮫ䝁䞁䝢䝳䞊䝔䜱䜽䝇≀㉁䜢ᵓᡂ䛩䜛㟁Ꮚ䛸ཎᏊ᰾䛾୧᪉䛻㔞ᏊຊᏛ䜢㐺⏝䛩䜛➨୍ཎ⌮䝅䝭䝳䝺䞊䝅䝵䞁ᢏ⾡䜢㛤Ⓨ䛧᪂≀ᛶ䜢᥈ᰝ୰すᐶ䠄኱㜰኱Ꮫ㻌 ᕤ䠅ୗྖ㞞❶䠄኱㜰኱Ꮫ䝘䝜䝉䠅ᚋ⸨ⱥ࿴䠄኱㜰኱Ꮫ㻌 ᕤ䠅
Dino Wilson(኱㜰኱Ꮫ㻌 ᕤ䠅➟஭⚽᫂䠄኱㜰኱Ꮫ㻌 ᕤ䠅ᐇ㦂≀㉁୰䛾䝥䝻䝖䞁䛾㔞Ꮚ⌧㇟䜢┤᥋ほᐹ䛩䜛ඹ㬆᰾཯ᛂἲ䠄NRA䠅•㔞ᏊຊᏛⓗ⢏Ꮚ䜢䝥䝻䞊䝤䛸䛩䜛䝭䝳䞊䜸䞁䝇䝢䞁ඹ㬆ἲ䠄μSR䠅Markus Wilde(ᮾி኱Ꮫ㻌 ⏕◊䠅⚟㇂ඞஅ(ᮾி኱Ꮫ㻌 ⏕◊)䝍䞊䝀䝑䝖㻌 э䞉⾲㠃䞉䝃䝤⾲㠃䚸䝘䝜⤖ᬗ䚸䝞䝹䜽⤖ᬗ䛻䛚䛡䜛䝥䝻䝖䞁䞉䝭䝳䞊䜸䞁㔞Ꮚ≧ែゎ᫂䞉䝥䝻䝖䞁㛵୚཯ᛂᶵᵓゎ᫂䠄㔞Ꮚᖸ΅䚸䝣䜱䝹䝍䝸䞁䜾䚸㔞Ꮚ䝖䞁䝛䝹䠅䞉䝥䝻䝖䞁㔞Ꮚ┦䛾᥈⣴䠄㧗ᅽỈ⣲㔞Ꮚ┦䚸㧗άᛶゐ፹䠅Naniwa codes¾ NANIWA is the first principles quantum mechanicalcalculation code for atomic motions near and/or in thematerials. 㻌 㻌㻌 㻌 㻌 䝟䝷䝯䞊䝍䝣䝸䞊䛾⌧ᐇ≀㉁䛾㔞Ꮚ䝅䝭䝳䝺䞊䝅䝵䞁¾ Two kinds of Naniwa codes.
Naniwa-2001 is a quantum mechanical version of thefirst principles molecular dynamics (MD) calculations,for reactions. [Scattering theory]㻌 㻌䠠䡅䡊䡋
Naniwa-Static is a nucleus version of the first principles
quantum state calculations.㻌 㻌 㻌 㻌 㻌 㻌୰すOur quantum simulation scheme: Naniwa
Interactions between nucleus is calculated
by DFT based first principle calculations

Potential energy
for nucleus motions: U n (R)Solve the Schrödinger
equation for nucleus
motionWave function for
nucleus motion

Derive thevarious
physicalquantities-Parameters are only
atomic number of elements-No fitting and no artificial procedure

Comparison between our simulation Naniwa-2001
and experimental results

Solve the scattering problem
Transmission㻌 probability
Adsorption, Absorption, desorption…

Rotational energy
distributions of hydrogenmolecule desorbing fromCu(111) surface䠠䡅䡊䡋with rotational, vibrational excitations
6D -potential
Energy Surface
V(r,θ,φ,X,Y,Z)

Our simulation results

square䠖 W.A.Dino, et al., PRL  (1997) 286.

Experimental datacircle

䠖H.A.Michelsen et al., J. Chem. Phys. (1993) 8294

No fitting parameters !

Comparison between our simulation Naniwa-2001
and experimental resultsSolve the scattering problem
Transmission㻌 probability
Adsorption, Absorption, desorption…

Rotational energy distributionsof hydrogen molecule desorbing
from Cu(111) surface䠠䡅䡊䡋with rotational, vibrational excitations

ศᏊᅇ㌿ JศᏊఙ⦰᣺ື ν୪㐍㐠ື 㹩
Our simulation results

square䠖 W.A.Dino, et al., PRL  (1997) 286.

Experimental datacircle

䠖H.A.Michelsen et al., J. Chem. Phys. (1993) 8294

No fitting parameters !

Comparison between our simulation Naniwa-Staticand experimental results

Calculate the Eigen states
for the atomic motions

3D-potential energy surface :V(x,y,z)Surface-normal vibrationenergy of Hydrogen atom
adsorbed on Cu(111) surface

୰すOur simulation
result *135 meVExperimentaldata **129 meV

5% error*K. Nobuhara et al., J. Appl. Phys. 96 (2004) 5020.

ffor EExcited
it d statet tElectron energy loss spectroscopy (EELS)**G. Lee, et al., Surf. Sci.  (2002) 229.

No fitting parameters !

Comparison between our simulation Naniwa-Staticand experimental results

Calculate the Eigen states
for the atomic motions

Surface-normal vibrationenergy of Hydrogen atom
adsorbed on Cu(111) surface

୰すOur simulation
result *135 meV

Experimental
data **129 meV

5% error*K. Nobuhara et al., J. Appl. Phys. 96 (2004) 5020.

ffor EExcited
it d statet tElectron energy loss spectroscopy (EELS)**G. Lee, et al., Surf. Sci.  (2002) 229.

No fitting parameters !

୰す䚸䠠䡅䡊䡋

⌧ᐇ≀㉁⣔䜈䛾㐺ᛂ㻌䞉Ỉ⣲䜶䝛䝹䜼䞊ᢏ⾡㛵㐃≀㉁㻌 ゎᯒ䛛䜙䝕䝄䜲䞁䜈㻌 㻌 㻌 ⇞ᩱ㟁ụ䠄㟁ᴟ䚸㟁ゎ㉁䠅䚸Ỉ⣲䝇䝖䝺䞊䝆䚸⇞ᩱ〇㐀㻌䞉䝭䝳䞊䜸䞁䝥䝻䞊䝤≀㉁ゎᯒ㻌 㻌 㻌 㻌 ≀㉁୰䝭䝳䞊䜸䞁䛾㔞Ꮚᵝែ䛾ゎ᫂䞉䝥䝻䝖䞁㔞Ꮚ┦䛾᥈⣴䠄㧗άᛶゐ፹䠅

Example:18.5 mass %H䠜LiBH4Sugiyama, et al.
PRB 81 (2010) 092103

ཎᏊ䛾㔞Ꮚ䝎䜲䝘䝭䜽䝇ィ⟬䝇䜻䞊䝮䛾ᣑᙇ㻌
1. ⌧䝁䞊䝗䛾㧗㏿໬䜰䝹䝂䝸䝈䝮2. ཎᏊ䛾㔞Ꮚ㐠ື䛻㛵䛩䜛㟁Ꮚບ㉳≧ែ䛾⧞䜚㎸䜏
3. ከཎᏊ䛾㔞Ꮚ䝎䜲䝘䝭䜽䝇ィ⟬䜈䛾㐨➽ୗྖ➨୍ཎ⌮ィ⟬䜢⏝䛔䛯᪂≀㉁タィ☢ᛶඖ⣲䜢ྵ䜎䛺䛔䝝䞊䝣䝯䝍䝹ᙉ☢ᛶ≀㉁䛾タィ(㛝ள㖄㖔ᆺCa䠄Sr)䝥䝙䜽䝍䜲䝗)ZB-CaAs㛝ள㖄㖔ᆺᵓ㐀䜢䝧䞊䝇䛻䛧䛯
GdN/CrAs㉸᱁Ꮚ䠄䝇䝢䞁☢Ẽ䝰䞊䝯䞁䝖䛜9.9PB䠄ᐇ㉁䝝䞊䝣䝯䝍䝹䠈䝔䞊䝷䞊䝯䜲䝗タィ䛾౛䠅)

GdNCrAs

12ୗྖタィ䛧䛯᪂≀㉁䛾ᵓ㐀Ᏻᐃᛶ¾ ᪂≀㉁䜢タィ䛧䛶䜒䠈ᵓ㐀Ᏻᐃᛶ䛜୙᫂䛺≀㉁䛻ᑐ䛧䛶䠈ᐇ㦂ᐇ᪋䛜㌋㌉䛥䜜䜛䠊
¾ CsCl-CaN䛾ᵓ㐀Ᏻᐃᛶ䜢ᙎᛶᐃᩘཬ䜃䝣䜷䝜䞁ィ⟬䛛䜙ㄪ䜉䛯䠊䠄⣙65GPa௨ୗ䛷ຊᏛⓗᏳᐃᛶ䜢ಖᣢ䠊
M. Geshi: Physica B405,517(2010)13᪂≀㉁䛾⏺㠃ຠᯝ䠄ZB-based㻌
CaAs/InSb and CaN/InSb㉸᱁Ꮚ䠅(a)CaAs/InSbୗྖ(b)CaN/InSb

Mtot=0.45PB/f.u.,
Mtot=0.61PB/f.u.
As1=0.32PB,As2=0.13PB
N1=0.60PB,N2=0.28PB
PDOS at the interface
M. Geshi, JCTN 6,2608(2009).
䝝䞊䝣䝯䝍䝹ᛶ䛿䛺䛟䛺䜛䛜䠈ᙉ☢ᛶ䛿ಖᣢ䠊 14

bcc Co/Cr(001)䛾
䛾⾲㠃䛾㟁Ꮚ≧ែୗྖ

Kawagoe, M. Geshi, T. Miyamachi, and S. Suga,
Applied Physics Express 2, 043001 (2009)䝥䝻䝖䞁㔞Ꮚ┦䛾᥈⣴㧗ᅽỈ⣲㔞Ꮚ┦ୗྖ䞉䝯䝍䝎䜲䝘䝭䜽䝇ᡭἲ䛾㐺⏝䞉Ỉ⣲㧗ᅽ┦㻌 ≀ᛶ᥈ᰝ㻌 㻌 㻌 䠯䡅䠤䠐➼䛾Ỉ⣲໬ྜ≀⣔㻌 㻌 㻌 㻌 㻌 㻌 →㻌 Ỉ⣲䛾㔠ᒓ໬䚸㉸ఏᑟ䛾Ⓨ⌧䛺䛹㻌 㻌 㻌 㻌 㻌 㻌 㻌 㻌 㻌 ᪂つ≀㉁┦䛾Ⓨぢ㻌㻌㻌㻌㻌㻌㻌㻌㻌㻌䞉㧗ᅽᴟ㝈⎔ቃ䠇䝥䝻䝖䞁䛾㔞Ꮚᛶ㻌 㻌 㻌 㻌 →㻌 㻌 ᪂つ≀ᛶ䝕䝄䜲䞁

7.5 GPa௨ୖ䛷䠤䠈䠠䛾஺᥮
N. W. Ashcroft, PhysRevLett.103.065701

䛣䜜䜎䛷䛾ྲྀ䜚⤌䜏
Direct Energy Minimization (DEM) ἲTotal energy Eᚋ⸨*ˆ < (r , r ,, r )d:rrr
H<(,,,)
12
N
1 2N
³
*<
³ (r1 , r2 ,, rN )<(r1 , r2 ,, rN )d:䜢ᴟᑠ䛻䛩䜛䜘䛖䛺 <(r1 , r2 ,, rN ) 䜢ኚศཎ⌮䛷ồ䜑䜛䚹

Path-Integral Renormalization Group (PIRG) ἲἼື㛵ᩘ <(r1 , r2 ,, rN ) 䜢⹫᫬㛫Ⓨᒎ䛥䛫䜛䛣䛸䛻䜘䜚ᇶᗏ≧ែ䜈ᑟ䛟Free Iterative-Complement-Interaction (FICI) ἲ䜽䝸䝻䝣䠉䝽䜲䞁䝇䝍䜲䞁䛾ᐃ⌮䛸LCE(Local Schrödinger Eq.)䜢⏝䛔䛶ᇶᗏ䜶䝛䝹䜼䞊䜢ồ䜑䜛< ri | c1H<0 ri  c2 H 2 <0 ri    cn H n <0 ri
17Neಶ䛾㟁Ꮚ䠇 Npಶ䛾䝥䝻䝖䞁䠇 Nμಶ䛾䝭䝳䞊䜸䞁䛛䜙ᡂ䜛ᚋ⸨⣔䛻䛚䛡䜛䠄᫬㛫䛻౫Ꮡ䛧䛺䛔ᐃᖖ≧ែ䛾䠅䝅䝳䝺䞊䝕䜱䞁Ĥ : ࣁ࣑ࣝࢺࢽ࢔ࣥ䜺䞊᪉⛬ᘧ< : Ἴື㛵ᩘ
Hˆ <(r1 , r2 ,, rN ) E<(r1 , r2 ,, rN )E :㻌㟁Ꮚ⣔䛾䜶䝛䝹䜼㟁Ꮚ

Hˆ䝥䝻䝖䞁

䝭䝳䞊䜸䞁· NP §·§ 1· Np §11¨¸¨¨¨ ' i  Vele (ri ) ¸¸  ¦ ' i  VP (ri ) ¸' i  V p (ri )  ¦ ¦¸¨
¸ i 1 ¨ 2m2mei 1©
P¹ i 1 © 2m p©
¹¹Ne1 N N
 ¦¦ V( e, p , P ) ( e, p , P ) (ri ,r j ) 㟁Ꮚ―䝥䝻䝖䞁―䝭䝳䞊䜸䞁㛫┦஫స⏝
2 i j
Ve e (ri ,r j )Ve  p (ri ,r j )'iri  r jee e pee ePri  r jwww

wxi2 wyi2 wzi2
2,Ve  P (ri ,r j )Ne  N p  N P )(N2e 2p2eele,V p  p (ri ,r j )ri  r j2

ri  r j
ri,VP  P (ri ,r j ),V p  P (ri ,r j )eP2
ri  r j,e p ePri  r j( xi , yi , zi ) 䛿 i ␒┠䛾⢏Ꮚ䛾ᗙᶆN e , N p , N P 䛿 㟁Ꮚ䚸䝥䝻䝖䞁䚸䝭䝳䞊䜸䞁⢏Ꮚᩘ
ee , e p , eP 䛿 㟁Ꮚ䚸䝥䝻䝖䞁䚸䝭䝳䞊䜸䞁䛾㟁Ⲵ

18

Direct Energy Minimization (DEM) ἲ䛾ᴫせᚋ⸨㠀┤஺ᇶᗏ䝉䝑䝖䜢⏝䛔䛶ຠ⋡ⓗ䛻┦㛵䜶䝛䝹䜼䞊䜢ồ䜑䜛᪉ἲ䛷䛒䜛ከ⢏Ꮚ⣔䛾Ἴື㛵ᩘ㻌 <㻌 㻌 䜢Slater⾜ิᘧ䛾⥺ᙧ⤖ྜ䛷⾲䜟䛩

Hˆ < r1 , V 1 , r2 , V 2 ,, rN , V N

E < r1 , V 1 , r2 , V 2 ,, rN , V N
L¦< r1 , V 1 , r2 , V 2 ,, rN , V N

I1A r1 J 1 (V 1 )I1A r2 J 1 (V 2 )I2A r1 J 2 (V 1 )  I NA r1 J N (V 1 )I2A r2 J 2 (V 2 )  INA r2 J N (V 2 )

A 1





I1A rN J 1 (V N ) I2A rN J 2 (V N )  I NA rN J N (V N )I jA r , J j (V ) 䛿䛭䜜䛮䜜䠍⢏ᏊἼື㛵ᩘ䛸䝇䝢䞁㌶㐨
᭱ᛴ㝆ୗ᪉ྥ] pA,kwEwI pA,(kold )*ຍ㏿䝟䝷䝯䞊䝍䞊
dE D pA , ] pA,kA
dD p

p 1,2,, N0Ἴື㛵ᩘ䛾᭦᪂

I pA,knewI pA,kold

p 1,2,, N䠍⢏Ꮚ㟁ᏊἼື㛵ᩘ I j r䜢ᅛ᭷≧ែ䛻ྥ䛛䛳䛶᭦᪂䛧䛶䜖䛟䚹䛣䛾䛸䛝䚸┤஺䞉つ᱁໬᮲௳䜢ㄢ䛥䛺䛔䚹
Aold D pA] pA,kFull-CI ἲ䜘䜚䜒ᑡ䛺䛔ᩘ䛾
Slater ⾜ิᘧ䛷┦㛵䜶䝛䝹䜼䞊䜢ぢ✚䜒䜛䛣䛸䛜䛷䛝䜛䚹
19

ᚋ⸨

DEM䛾
䛾䝔䝇䝖ィ⟬ -Ỉ⣲ศᏊ䠄H2 䠅- 㻌඲䜶䝛䝹䜼䞊㻌 (a.u.)

Hartree-Fock

Exact *Correlation energyཎᏊ㛫㊥㞳 (bohr)ᖹ⾮ཎᏊ㛫㊥㞳 䛾䛸䛝䛾㟁Ꮚᐦᗘศᕸ(䠎ಶ䛾ཎᏊ䜢ྵ䜐ᖹ㠃ୖ)* ཝᐦゎ䠖W. Kolos and L. Wolniewicz, J. Chem. Phys., 49 (1968) 404.
20௒ᖺᗘᚋ⸨• DEMἲἲ䛾㟁Ꮚ䞉䝥䝻䝖䞁䞉䝭䝳䞊䜸䞁⣔㔞Ꮚ≧ែ㻌 㻌 㻌 䝅䝭䝳䝺䞊䝅䝵䞁䝥䝻䜾䝷䝮䜈䛾Ⓨᒎ• ᒁᅾᇶᗏ䝉䝑䝖䠄Gaussian䛺䛹䠅䛾ᑟධ䛻䜘䜛㻌 㻌 LCAO DEM 䛾㛤Ⓨḟᖺᗘ௨㝆• ☢ሙୗ䛷䛾䝅䝭䝳䝺䞊䝅䝵䞁䝥䝻䜾䝷䝮㛤Ⓨ• ࿘ᮇቃ⏺᮲௳䛾ᑟධ• ᅛయᮦᩱ䜈䛾㐺⏝• FICIἲ䛺䛹䚸௚䛾ィ⟬ᡭἲ䛾᳨ウ21䝥䝻䝖䞁䛾㔞Ꮚᛶ䠖䝥䝻䝖䞁䞉䝭䝳䞊䜸䞁⛉Ꮫ䝁䞁䝢䝳䞊䝔䜱䜽䝇≀㉁䜢ᵓᡂ䛩䜛㟁Ꮚ䛸ཎᏊ᰾䛾୧᪉䛻㔞ᏊຊᏛ䜢㐺⏝䛩䜛➨୍ཎ⌮䝅䝭䝳䝺䞊䝅䝵䞁ᢏ⾡䜢㛤Ⓨ䛧᪂≀ᛶ䜢᥈ᰝᐇ㦂≀㉁୰䛾䝥䝻䝖䞁䛾㔞Ꮚ⌧㇟䜢┤᥋ほᐹ䛩䜛ඹ㬆᰾཯ᛂἲ䠄NRA䠅•㔞ᏊຊᏛⓗ⢏Ꮚ䜢䝥䝻䞊䝤䛸䛩䜛䝭䝳䞊䜸䞁䝇䝢䞁ඹ㬆ἲ䠄μSR䠅

୰すᐶ䠄኱㜰኱Ꮫ㻌 ᕤ䠅ୗྖ㞞❶䠄኱㜰኱Ꮫ䝘䝜䝉䠅ᚋ⸨ⱥ࿴䠄኱㜰኱Ꮫ㻌 ᕤ䠅
Dino Wilson(኱㜰኱Ꮫ㻌 ᕤ䠅➟஭⚽᫂䠄኱㜰኱Ꮫ㻌 ᕤ䠅Markus Wilde(ᮾி኱Ꮫ㻌 ⏕◊䠅⚟㇂ඞஅ(ᮾி኱Ꮫ㻌 ⏕◊)䝍䞊䝀䝑䝖㻌 э䞉⾲㠃䞉䝃䝤⾲㠃䚸䝘䝜⤖ᬗ䚸䝞䝹䜽⤖ᬗ䛻䛚䛡䜛䝥䝻䝖䞁䞉䝭䝳䞊䜸䞁㔞Ꮚ≧ែゎ᫂䞉䝥䝻䝖䞁㛵୚཯ᛂᶵᵓゎ᫂䠄㔞Ꮚᖸ΅䚸䝣䜱䝹䝍䝸䞁䜾䚸㔞Ꮚ䝖䞁䝛䝹䠅䞉䝥䝻䝖䞁㔞Ꮚ┦䛾᥈⣴䠄㧗ᅽỈ⣲㔞Ꮚ┦䚸㧗άᛶゐ፹䠅䝭䝳䞊䜸䞁μ䠉㻌 䝭䝳䞊䜸䞁㻌 →㻌 㟁Ꮚ㻌 䠇㻌 㻌 䝭䝳䞊䝙䝳䞊䝖䝸䝜䠇㻌 ཯㟁Ꮚ䝙䝳䞊䝖䝸䝜μ䠇㻌 ཯䝭䝳䞊䜸䞁㻌 →㻌 㝧㟁Ꮚ㻌 䠇㻌 ཯䝭䝳䞊䝙䝳䞊䝖䝸䝜㻌 䠇㻌 㟁Ꮚ䝙䝳䞊䝖䝸䝜Particle statistics

Fermionic

Mass:

105.658369(9) MeV/c2

Mean lifetime:

2.19703(4)×10−6 sec

Electric charge:

e

Spin:

1⁄

2

䝭䝳䞊䜸䞁䝇䝢䞁ᅇ㌿䠖μSR≀㉁ෆ☢ሙ㝧㟁Ꮚᨺฟ㧗ឤᗘ䛾☢Ẽ
Spin:1⁄2☢Ẽᅇ㌿ẚ (gyromagnetic ratio) 䠖135.53 MHz/Tᐃ᪂Ꮫ⾡㡿ᇦ◊✲࣭࢟ࢵࢡ࢜ࣇ࣭࣑࣮ࢸ࢕ࣥࢢ䛂䝁䞁䝢䝳䠉䝔䜱䜽䝇䛻䜘䜛≀㉁䝕䝄䜲䞁䠖」ྜ┦㛵䛸㠀ᖹ⾮䝎䜲䝘䝭䜽䝇䛃
September 18, 2010
University of Tokyo

Hydrogen Absorption Mechanism atMetal Single Crystal Surfaces and Nanoparticles
Markus Wilde
Institute of Industrial Science, University of TokyoFocus: Hydrogen Absorption by Transition Metals
Important Industrial Applications:• Hydrogen Storage (in Metal Hydrides)• Catalysis (of Hydrogenation Reactions: Olefins, Fuel Cell HOR)=> Demand for control of H-absorption capacity and charge/release kinetics

gas-phase H2

Goal: Obtain microscopic(atomistic) understanding

dissociative
adsorptionof absorption andprocesses !

surface-HHhydrogen-poor
phase (D)zkpenpenetration'subsurface'-Habsorptionhydrogen-richlayer (hydride)phaseboundary྾཰

desorption
H2kads㐍ධ

Kdiff-Din-diffusion'bulkdissolved’hydrogentransition metal or alloy (Pd, Ni, Ti, Y, Zr, Mg ...)

0=> Clarification of the surface-subsurface transition (penetration) mechanism

H Absorption at Metal Surfaces: The Microscopic Perspective
Under-coordinated surface atoms generally bind adsorbed H more strongly thanmetal atoms in the bulk => H-absorption is necessarily activated!
H/Pd(100):

䍜ĺ6XUIDFH(S = -0.53 eV/H.

'Hs: > 0 endothermic< 0 exothermic䍜ĺ%XON IFF (B = -0.1 eV/H (= 'Hs).
ĺµ6XEVXUIDFH¶(S < ESS (-0.19 eV) < EB

1H220BTop view'HsSSSSide view

4-fold hollowSurface
SubsurfaceBulkH2H2HHz0H2time

 Exposure to H2 gas will saturate the surface quickly with adsorbed H.
 Hydrogen absorption proceeds slowly, from a fully H-covered surface.

Unique Experimental Approach: TDS + NRA
Hydrogen detection techniques:
H2 Desorption signal (TDS)

Thermal Desorption Spectroscopy:
ĺDGVRUSWLRQDEVRUSWLRQHQHUJ\RI+VSHFLHVĺGHVWUXFWLYHPHDVXUHPHQWĺQRLQIRUPDWLRQRQ+ORFDWLRQ RQEHORZVXUIDFH

Surface-H signal (Hs)
Subsurface-H signal (Hss)100200300
400500Temperature (K)600

Nuclear Reaction Analysis via 1H(15N,DJ)12C: (Eres=6.385 MeV, *=1.8 keV)ĺGLVWLQFWLRQRIVXUIDFH-adsorbed from absorbed H (nm-scale)ĺSimultaneous detection of adsorbed/absorbed and desorbing H!
Jv [Hsurface]
Ei=Eres
15N2+ ion beam

NExperimentalJv [Habsorbed]

J-detector

Ei>Eres0probing depth:z(Ei)= (Ei-Eres)/(dE/dz)(stopping power)

Surface/absorbed H (NRA)H2 Desorption signal

Resonant Nuclear Reaction Analysis via 1H(15N,DJ)12C
Facts & Figures on Near-Surface (~20 nm) Hydrogen Depth Profiling (single crystals)
depth [nm]-4 -2 0 2 4 6 8 10 12 14 16

Integral: H coverage (quantitative)

Pd(100) in

FWHM: Vibrational Zero-Point Energies(Ex, Ez)

3x10-6 Pa H2

Shape: Near-Surface H-distributionHss06.38
15



Information Yield Surface Resonance
Peak (Eres = 6.385 MeV)

HsT < 160 Ka)

J ray yield [cts/PC]

150



6.40

6.42

6.44

Non-destructive measurement
In-situ treatments: H-uptake kinetics,thermal stability (depth-resolved)

N ion energy [MeV]

Detection LimitSurface H Coverages: 1% ML (~1013 cm-2)
Absorbed (Subsurface/Bulk) H concentrations: ~400 ppm (~1018 cm-3)

Depth resolution (limited by Doppler-broadening at the surface)
Near-surface: < 3 nm (N.I.), < 1 nm (grazing incidence) ĺ$SSOLFDWLRQWRNanocrystals

K. Fukutani et al., PRL 88 (2002) 116101䠊

M. Wilde et al., Phys. Rev. B 77 113412 (2008).

Surface to Subsurface/bulk transitions at single crystalsĺ3K\V5HY%78, 115411 (2008).

A ‘simple’ question:

Can surface-adsorbed H penetrate a clean, perfectly flat surface?
zPd(100):Hĺ6XUIDFH-H desorbs (at ~330 K).

0ĺ6XEVXUIDFH-absorbed H bypasses the surface-H layer (at 180K).

'T

Ti(0001):ĺ6XUIDFH-H is absorbed into the bulk (near 320 K).

Hss100

200

300
400
500
Temperature (K)600

H2 Desorption signal (TDS)

H2Ti(0001)(T<600 K)
HsHb

H2 Desorption signal
Surface-H signal (Hs)

Surface H coverage (NRA)Hs

H2 Desorption signal
Surface-H signal (Hs)
Subsurface-H signal (Hss)Surface/absorbed H (NRA)

Pd(100)H2 Desorption signal (TDS)ĺ%XON-absorbed H desorbs from an empty surface (above 650 K).

bulk-H(Hb)

200

300

400

500

600

700

Temperature (K)=> Opposite behavior of surface-adsorbed H atoms on Pd(100) vs. Ti(0001)

800

Identification of H-absorption mechanism: H/Pd(110)
Hydrogen Absorption/Desorption Behavior
H2Pd(110):

1. Preadsorbed Ds

2.post-dosed H2Hs

H2130 K

NRA: Absorbed H!

D2Dss

1.25 L D2 + 1000 L H2 (both at 130 K)
H2HD
D2-1280x10

QMS ion current [A]

Hss

HD60
-> D2 is included in alpha-1 peak (!)
40ĺ62KQR0:LOGH.)XNXWDQL

20in preparation

0150

200

250

300

350

400

Temperature [K]ĺ*DV-phase H2 helps surface-adsorbed D-atoms to penetrate the surface!

Pd(110): No surface-subsurface transition of H without H2 gas!
Hydrogen Absorption Mechanism
H2Pd(110):Hs

1. Hsno H2no Hss (!)

130 K

No absorbed H!

-12

QMS ion current [A]

140x100.8 L H2 at 130 K
quenched to 85 K
kept 80 sec at 130 K

1201008060ĺ62KQR0:LOGH.)XNXWDQL

40
20

in preparation

0150

200

250

300

350

400

Temperature [K]ĺ:LWKRXWJDV-phase H2 , surface-adsorbed H-atoms stay on the surface!

Pd(110): Isotope effect in absorption of H2 and D2Hydrogen Absorption Mechanism

H2D2 or H2HsHsPd(110):D2 vs. H2Hss

100-160 K-9

H2 (130 K)

50x10ĺ62KQR0:LOGH.)XNXWDQL

40

TDS Integral [arb. units]no Hss (!)

in preparation
D2 (160 K)

30
D2 (130 K)
D2 (100 K)

20
from Arrhenius plot*
E H=0.031 eV
10*

E D=0.058 eV
0500

1000

1500

2000

2500

One order smaller than
expected for subsurface
transition of surfaceadsorbed H-atoms!

3000

Exposure [L]ĺNormal isotope effect (H faster than D) in subsurface population !
ĺOpposite to bulk-diffusion (D faster than H)!

Hydrogen Absorption in Al2O3-supported Pd nanocrystals
Analysis of H distribution in 5.85 Å (2.6 ML) Pd on Al2O3 at 90 K, 2·10-5 Pa H2.
depth z [nm]-4-2024J-yield [counts/PC]

250

68Experiment
Surface H
Absorbed H

200

17.5 nm x 17.5 nm

150

Di=75o100
15N

5050 nm x 50 nm

JHPdPdh~2 nm

06.37

6.38

6.39

6.40

6.41

Al2O3/NiAl(110)15N ion energy [MeV]• 4-fold enhanced depth resolution in 75o grazing incidence angle NRA.
• NP-absorbed H (arrow) can be probed independently from surface-adsorbed H.
=> Pd-NP stabilize absorbed H with 2-3 fold higher heat of solution than bulk Pd.
( ĺNot a surface-adsorption effect!)
M. Wilde et al., Phys. Rev. B 77, 113412 (2008).

H-Solution in Metallic Nanocrystals ĺEssential for Catalysis!
'HS [eV]

Bulk

Nanocrystal

Pd-(0.1…0.15)
exothermic-0.28㼼0.02(@ H/Pd<0.2)+0.48 Strongly
endothermic=> Does HAbsorption
occur?

PtHeat of H solution (''Hs) differs
drastically (from bulk value)
in nanomaterials:
ĺ&DWDO\VLV+\GURJHQ6WRUDJH

Proved:Al2O3support

Olefin hydrogenation catalysis requires
volumePd Cluster-absorbed H (!)
Model Catalyst

M. Wilde, K. Fukutani, M. Naschitzki, H.-J. Freund, Phys. Rev. 䠞 77, 113412 (2008).
M. Wilde, S. Schauermann et al., Angew. Chem. Int. Ed. 47, 9289 (2008).

Hydrogen Absorption in Platinum-Nanocrystals (!) : Pt/ Al2O3
Depth resolved Real-time H-Uptake & Thermal stability => 'Hs !

100 nm x 100 nm

1.0z=0normalized J-yield

200150100

4 Å Pt/Al2O3/NiAl(110)
Courtesy of S. Shaikhutdinov, FHI

0.80.60.40.2z = 5 nm

50200 K100 K
2000

4000

6000

200

8000

15N2+Pt

h~1-2 nm

Al2O3/NiAl(110)~6.5-10 nm

J-yield [counts/PC]-2H

300

350

400

450

500

Depth [nm] (x4)
24
60810

T = 100 K
300

6x10-3 Pa H2> 2 hrs

200
10006.37

M. Wilde, S. Ohno, K. Fukutani, in preparation

250

Temperature [K]Time [s]75op=6x10-3 Pa H20.000Surface H
Absorbed H

6.38

6.39
156.406.41

6.426.43N ion energy [MeV]=> Nanocrystal size information is needed to derive absolute H-concentrations (and 'Hs)!

Plans & Objectives, Suggestions, Requests…
Single Crystals
ĺ&ODULI\WKHVXUIDFHSHQHWUDWLRQPHFKDQLVPLQSUHVHQFHRIJDVSKDVH+2!
ĺ,QYROYHPHQWRIPROHFXODUSUHFXUVRUVWDWHV"'LVVRFLDWLRQĺ:KHUH"

Nanoparticles
ĺ&ODULI\WKHRULJLQRIVWURQJ+-stabilization in the nanocrystals.
ĺ(VWDEOLVKVL]H-dependence of 'Hs.

Absorbed Hydrogen
Role in Olefin Hydrogenation:

Al2O3support

volumeĺ0HFKDQLVP"=> Design of ideal hydrogen storage metals and hydrogenation catalysts!