ᚑくᄢቇℂᎿቇ⎇ⓥႎ๔
J. Fac. Sci. Tech., Seikei Univ.
Vol.47 No.2 (2010) pp.37-38
㧔․೎⎇ⓥ⾌ߦଥࠆ⺰ᢥ㧕࠽ࡁࠞ࡯ࡏࡦⶄว᧚ᢱ⴫㕙࡮⇇㕙ߩࡔࠞੑࠢࠬ૒‫ ᧁޘ‬ᚑᦶ*1㧘ጟᧄ ⧷ື*2, ᢪ⮮ Ṽ⥝*2, ᧼᧛ ⾫᣿*3

Mechanics of Surface and Interface of Nanocarbon Hybrid Materials
Naruo SASAKI㧖1, Hideaki OKAMOTO㧖2, Hirooki SAITOH㧖2, Noriaki ITAMURA㧖3,ABSTRACT㧦 Recently carbon materials have attracted many attentions as electronic, magnetic, opticaland mechanical devices. We have so far numerically studied tribology of the carbon materials,
particularly atomic-scale friction and wear at carbon interfaces formed by graphene, fullerene, andcarbon nanotube by molecular mechanics simulations. First atomic-scale wear of graphene/grapheneinterface induced by friction-force microscopy tip is investigated. The transition from the nano-tip state
to the graphene-tip state is revealed. Next, during the peeling process of the graphene sheet from thegraphite surface, the effect of the superlubricity on the peeling process is clarified.
Keywords㧦Tribology, friction, adhesion, graphite, friction force microscopy
㧔Received September 24, 2010㧕ᵈ⋡ࠍ㓸߼ߡ޿ࠆ὇⚛᧚ᢱߩห⚛૕ߦ⌕⋡ߒ㧘․ߦߘߩ

㧝㧚ߪߓ߼ߦ౐ຬⅣࡀ࠶࠻ࡢ࡯ࠢߢᒻᚑߐࠇࠆ⇇㕙ߩේሶࠬࠤ࡯࡞៺ ㄭᐕߩ࠽ࡁ࠹ࠢࡁࡠࠫ࡯ߩ⊒ዷߦࠃߞߡᓸ⚦ടᎿߩࡃᡂ࡮៺⠻ߩታ㛎⊛ 1)㨪3)㧘ᢙ୯⊛ 4)㨪11)⎇ⓥࠍㅴ߼ߡ޿ࠆ‫ޕ‬࡝ࠛ࡯࡚ࠪࡦߪ㛳ߊ߶ߤᄙጘߦᷰࠅ㧘ࡑࠗࠢࡠࡑࠪࡦ㧘

ᧄⓂߢߪ 2009 ᐕᐲ․೎⎇ⓥ⾌‫ⶄࡦࡏ࡯ࠞࡁ࠽ޟ‬ว᧚ᢱ⴫࠽ࡁࡑࠪࡦߩታ↪ൻ߳ߩᄞ߇⤘ࠄ߻߇㧘⃻ታߦߪ໧㗴ߪ㕙࡮⇇㕙ߩࡔࠞ࠾ࠢࠬ‫ߢޠ‬ㅴ߼ࠄࠇߚ⎇ⓥߩਛ߆ࠄ㧘․◲නߢߪߥ޿‫ߩߘޕ‬ℂ↱ߪࡒࠢࡠߩ਎⇇ߢߪᯏ᪾߇േ߈

ߦࠣ࡜ࡈࠚࡦߢᒻᚑߐࠇߚ὇⚛⇇㕙ߩ៺ᡂ㧘ಝ⌕ࠍಽሶߦߊߊߥߞߡߒ߹߁߆ࠄߢ޽ࠆ‫߫߃଀ޕ‬ඨᓘ 1cm ߩ⃿૕ജቇᴺߢ⺞ߴߚ⚿ᨐࠍႎ๔ߔࠆ‫ޕ‬ߪ㧘1nm ߩ⃿ߩ႐ว㧘1cm ߩ⃿ߦᲧߴߡ 1000 ਁ୚ߦ߽෸

㧞㧚ࡕ࠺࡞ߣ⸘▚ᚻᴺ

ߣ 1nm ߩ⃿૕ࠍᲧセߔࠆߣ㧘⴫㕙Ⓧߩ૕ⓍߦኻߔࠆᲧ₸߮㧘⴫㕙ߩലᨐ߇ 1000 ਁ୚ߦߥࠆ‫⴫ᤨߩߎޕ‬㕙ࠍ੺ߒߡᧄ⎇ⓥߢߪ㧘ಽሶജቇࠪࡒࡘ࡟࡯࡚ࠪࡦࠍ↪޿ߡࠣ࡜௛ߊᓸⷞ⊛ߥ‛ℂ⚿ว࡮ൻቇ⚿ว߇㗼࿷ൻߒߡ៺ᡂജ߇
ᭂ߼ߡᄢ߈ߊߥࠆ‫ߢࠢ࠹ࡁ࠽ࠅ߹ߟޕ‬૞ᚑߦᚑഞߒߚᓸ

ࡈࠚࡦ/ࠣ࡜ࡈࠚࡦ⇇㕙ߩ࠻࡜ࠗࡏࡠࠫ࡯․ᕈࠍᢙ୯⊛⚦ᯏ᪾ࠍേ߆ߒᆎ߼ߡ߽㧘૗ࠄ߆ߩ߈ߞ߆ߌߢ៺ᡂ߇↢ߦ⺞ߴߚ‫ࡦࠚࡈ࡜ࠣޕ‬ౝㇱߩ὇⚛ේሶࡀ࠶࠻ࡢ࡯ࠢߩ౒ߓߡᯏ᪾߇ᱛ߹ߞߡߒ߹߁น⢻ᕈ߇㜞޿‫ࠢࠗࡑߪࠇߎޕ‬᦭⚿วࠍ⴫ߔ Tersoff ࡐ࠹ࡦࠪࡖ࡞ 12)ߣ㧘࠽ࡁត㊎-ࠣ࡜ࡠ࡮࠽ࡁࡑࠪࡦᏒ႐ߩ᜛ᄢࠍផㅴߔࠆ਄ߢᄢ߈ߥ㓚ኂߣࡈࠚࡦ㧘ࠣ࡜ࡈࠚࡦ-ࠣ࡜ࡈࠚࡦ㑆ߩ㕖⚿ว⋧੕૞↪ࠍ⴫ߥࠅᓧࠆ‫↥࡯ࠫࡠࡁࠢ࠹ࡁ࠽ߡߒ߁ߎޕ‬ᬺߩⷐ⺧߆ࠄ㧘ߔ LJ ࡐ࠹ࡦࠪࡖ࡞ 13)㨪14)ߩ๺ߢ⴫ࠊߐࠇࠆోࠛࡀ࡞ࠡ࡯

ᓸዊ㗔ၞߢߩ៺ᡂࠍࠦࡦ࠻ࡠ࡯࡞ߔࠆ⎇ⓥ㧘․ߦ⿥ૐ៺

ࠍ㧘Polak-Rebiere ࠲ࠗࡊߩ౒ᓎ൨㈩ᴺ(CG)ᴺ 15)ࠍ↪޿ߡᡂ࡮⿥ẢṖ⎇ⓥߩ࠾࡯࠭߇⊒↢ߔࠆ‫৻ޕ‬ᣇ㧘ᓸዊ㗔ၞߢᭂዊൻߔࠆ‫ޕ‬Ḱ㕒ㆊ⒟ߩㄭૃ߇ᚑ┙ߔࠆ᧦ઙਅ㧘ߔߥࠊ⃻ࠇࠆᄢ߈ߥ៺ᡂജࠍធ⌕ߦ೑↪ߔࠆߣ޿߁ోߊㅒᣇะ

ߜ v → 0㧘T = 0 K ߩᭂ㒢ߢ㧘࠽ࡁត㊎㧘㕖๟ᦼቅ┙ࠣ࡜ߩ⎇ⓥ࠾࡯߽࠭ሽ࿷ߔࠆ‫ߢߎߘޕ‬ᚒ‫ߪޘ‬㧘㔚ሶ㧘శቇ㧘ࡈࠚࡦࠪ࡯࠻㧘๟ᦼ⊛਄ጀࠣ࡜ࡈࠚࡦࠪ࡯࠻ߩṖࠅ㧔⿛⏛᳇㧘ᯏ᪾ߥߤ޽ࠄࠁࠆ࠲ࠗࡊߩ࠺ࡧࠔࠗࠬ᧚ᢱߣߒߡ

ᩏ㧕ߦኻߒߡ㧘ࡕ࠺࡞ో♽ߩ᭴ㅧᦨㆡൻࠍⴕߞߚ‫ޕ‬

㧦ℂᎿቇㇱ‛⾰↢๮ℂᎿቇ⑼ ᢎ᝼ (naru@st.seikei.ac.jp)*1*2㧦Ꮏቇ⎇ⓥ⑼‛ℂᖱႎᎿቇኾ᡹ ୃ჻ቇ↢*3

㧦ℂᎿቇㇱ‛⾰↢๮ℂᎿቇ⑼ ഥᚻ㧙㧙㧠㧚ࠣ࡜ࡈࠚࡦߩᒁ߈೸߇ߒㆊ⒟ 5)㨪7)㧔ࠣ࡜ࡈࠚ㧟㧚៺ᡂജ㗼ᓸ㏜ߩ⿛ᩏㆊ⒟ 4)㧔ត㊎/ࠣ࡜ࡈࠚࡦࡦ/ࠣ࡜ࡈࠚࡦ⇇㕙㧕⇇㕙㧕వߕᄙጀࠣ࡜ࡈࠚࡦၮ᧼਄ߢ࠽ࡁࠬࠤ࡯࡞ត㊎ࠍ᳓ᐔ ᰴߦࠣ࡜ࡈࠚࡦࠪ࡯࠻ߩࠣ࡜ࡈࠔࠗ࠻ၮ᧼߆ࠄߩ࠽ࡁ⿛ᩏߔࠆ㓙ߩࠣ࡜ࡈࠚࡦ↢ᚑㆊ⒟ࠍ⺞ߴߚ㧔Fig.1㧔a㧕㧕‫ޕ‬ࠬࠤ࡯࡞ᒁ߈೸߇ߒㆊ⒟ࠍ⺞ߴߚ㧔Fig.2㧔a㧕㧕‫ࡈ࡜ࠣޕ‬࠽ࡁត㊎ࠍ৻ቯ㜞ߐࡕ࡯࠼ߢ㧨1230㧪ᣇะߦ⿛ᩏߒߚᓟ㧘ࠚࡦࠪ࡯࠻ߩਛᄩㇱಽࠍᜬߞߡᒁ߈೸߇ߔ႐ว㧘ਛᄩઃㅒᣇะߦరߩ૏⟎߹ߢ⿛ᩏߔࠆ‫ޕ‬ត㊎ࠍࠣ࡜ࡈࠚࡦ⹜ᢱㄭߩㇱಽ⊛ߥᒁ߈೸߇ࠇ߇⿠ߎࠅ㧘ജᦛ✢ߦਇㅪ⛯ߥࠫߦ᛼ߒߟߌࠆߦ઻ߞߡ㧘ࠣ࡜ࡈࠚࡦጀ߇࠽ࡁត㊎ߦઃ⌕ࡖࡦࡊ߇⃻ࠇࠆ‫ߦࠇߘޕ‬ኻᔕߒߡࠣ࡜ࡈࠚࡦࠪ࡯࠻ߪࠕߒߡṖࠆࠃ߁ߦߥࠅ㧘࠽ࡁត㊎ࡕ࡯࠼߆ࠄࠣ࡜ࡈࠚࡦត࡯࠴⁁ߩᄌᒻࠍ⿠ߎߒߚ‫৻ޕ‬ᣇࠣ࡜ࡈࠚࡦࠪ࡯࠻ߩ┵ߩ㊎ࡕ࡯࠼߳ߩォ⒖߇⃻ࠇࠆ‫ޕ‬ᐔဋ⩄㊀߇Ⴧടߔࠆߦߟࠇㇱಽࠍᜬߞߡᒁ߈೸߇ߔ႐ว㧘ේሶࠬࠤ࡯࡞៺ᡂߩലᨐߡ㧘ᐔဋ᳓ᐔജߪ㧘࠽ࡁត㊎ࡕ࡯࠼ߢᕆỗߦჇടߒߡࡇ߇⃻ࠇࠆ‫࠻ࠗࠔࡈ࡜ࠣ߇࠻࡯ࠪࡦࠚࡈ࡜ࠣޕ‬ၮ᧼ߣ㕙ធ࡯ࠢࠍ␜ߒ㧘ߘߩᓟࠣ࡜ࡈࠚࡦត㊎ࡕ࡯࠼ߢᷫዋߒߡ⩄⸅ߒߡ޿ࠆᤨ㧘ࠪ࡯࠻ߪࠣ࡜ࡈࠔࠗ࠻ၮ᧼਄ࠍේሶࠬࠤ

㨋㊀ߦࠃࠄߕ߶߷৻ቯߩ୯ࠍߣࠆ㧔Fig.1㧔b㧕㧕‫⚿ߩߎޕ‬ᨐ࡯࡞ߢࠬ࠹ࠖ࠶ࠢࠬ࡝࠶ࡊㆇേࠍ⿠ߎߒߥ߇ࠄ᳓ᐔᣇะ

ߪ㧘࠽ࡁត㊎ࡕ࡯࠼߇ត㊎-ࠣ࡜ࡈࠚࡦᦨᄖጀ㑆ߩ៺ᡂࠍߦṖࠆ‫ޕ‬ᓥߞߡജᦛ✢ߦߪࠣ࡜ࡈࠔࠗ࠻ࠪ࡯࠻߇Ṗࠆᣇᬌ಴ߒ㧘ࠣ࡜ࡈࠚࡦត㊎ࡕ࡯࠼߇㧘ࠣ࡜ࡈࠚࡦᦨᄖጀ-ะߩᩰሶ๟ᦼ߇⃻ࠇࠆ㧔Fig.2㧔b㧕㧕‫ࠪࡦࠚࡈ࡜ࠣߦᦝޕ‬╙ 2 ጀ㑆㧘߹ߚߪ╙ 2 ጀ-╙ 3 ጀ㑆ߦ௛ߊౝㇱ៺ᡂࠍᬌ಴

࡯࠻ߩ⥄↱┵߇ࠕ࡯ࡓ࠴ࠚࠕဳ߆ࠫࠣࠩࠣဳ߆ߦࠃߞߡ㧘ߔࠆ੐ࠍ␜ߒߡ޿ࠆ‫ࡦࠚࡈ࡜ࠣߥ߁ࠃߩߎޕ‬ត㊎↢ᚑㆊࠪ࡯࠻ߩේሶࠬࠤ࡯࡞Ṗࠅߦ㆑޿߇⃻ࠇߚ‫ߩࠄࠇߎޕ‬⍮⒟ߩℂ⸃ߪේሶࠬࠤ࡯࡞៺⠻ߩ⚛ㆊ⒟ߩࡔࠞ࠾࠭ࡓߩ⸃

⷗ߪ㧘៺ᡂജ㗼ᓸ㏜ត㊎/⹜ᢱ⇇㕙ߢߩࠣ࡜ࡈࠚࡦࠪ࡯࠻

᣿ߦߟߥ߇ࠆ‫ޕ‬ߩේሶࠬࠤ࡯࡞៺ᡂߩ⋥ធⷰኤߩ⹏ଔᴺߣߒߡᓎ┙ߟߛ(a)Nanotip

Forwardߌߢߥߊ㧘ࠪ࡯࠻߇Ṗࠆᣇะߩ⚿᥏ゲߣ⥄↱┵ߩ᭴ㅧࠍ᳿ቯ಴᧪ࠆน⢻ᕈࠍ␜ໂߒߡ޿ࠆ‫ޕ‬

Backward

(a)

1st
2nd
3rd

Graphite Substrate

Intermediate< Fx >[pN]
0.1
1000.0550

Graphite Substrate

Nanotip00(b) 0–0.2

Force acting on thelifting edge Fz [eV/Å](b)

GrapheneSheet

Graphene Tip
10< Fz > [nN]

2.5㷬

–0.4

20

surfacecontact–0.6(KI C /QFGNQHVKRUWDUVTCVGKPVGTHCEG D /GCPNCVGTCNHQTEGCUCHWPEVKQPQHVJGOGCPNQCFKPIHQTEG

020linecontact
40

Lifting edge height z [Å](KI C /QFGNQHITCRJGPGUWDUVTCVGKPVGTHCEG
D (QTEGEWTXGTGHNGEVUUVKEMUNKRDGJCXKQTU㧙㧙Surf. Sci. Nanotech. 7, 783 (2009).

㧡㧚߅ࠊࠅߦ

6㧕 N. Sasaki, H. Okamoto, N. Itamura, and K. Miura: e-J.
Surf. Sci. Nanotech. 8, 105 (2010).

ᧄ⎇ⓥߢߪ㧘వߕᄙጀࠣ࡜ࡈࠚࡦၮ᧼ߦ៺ᡂജ㗼ᓸ㏜

7㧕 N. Sasaki, H. Okamoto, S. Masuda, K. Miura, and N.

ត㊎ࠍ᛼ߒߟߌߡ㧘ࠣ࡜ࡈࠔࠗ࠻៺⠻ߩේሶࠬࠤ࡯࡞⚛

Itamura: J. of Nanomat. 2010, 742127 (2010).

ㆊ⒟ࠍ⺞ߴ㧘ត㊎᛼ߒઃߌߦ઻߁࠽ࡁត㊎ࡕ࡯࠼߆ࠄࠣ

8㧕 N. Sasaki, N. Itamura, and K. Miura: J. Phys.:࡜ࡈࠚࡦត㊎ࡕ࡯࠼߳ߩォ⒖ࠍ⷗಴ߒߚ‫ޕ‬ᰴߦනጀࠣ࡜

Conference Ser. 89, 012001 (2007).

ࡈࠚࡦࠍࠣ࡜ࡈࠔࠗ࠻ၮ᧼⴫㕙߆ࠄᒁ߈೸߇ߔㆊ⒟ߢ㧘9㧕 N. Sasaki, N. Itamura, and K. Miura: Jpn. J. Appl. Phys.

㕙ធ⸅߆ࠄ✢ធ⸅߳ߩォ⒖ߣ㧘㕙ធ⸅ߦ߅ߌࠆ⿥ẢṖߩ

46, L1237 (2007).

ነਈࠍ᣿ࠄ߆ߦߒߚ‫ޕ‬

10㧕N. Itamura, K. Miura, and N. Sasaki: Jpn. J. of Appl.
Phys. 48, 030214 (2009)ෳ⠨ᢥ₂

11㧕N. Itamura, K. Miura, and N. Sasaki: Jpn. J. of Appl.
Phys. 48, 060207 (2009).

1㧕 K. Miura, S. Kamiya, and N. Sasaki: Phys. Rev. Lett. 90,055509 (2003).

12㧕J. Tersoff: Phys. Rev. Lett. 61, 2879 (1988).

2㧕 K. Miura, D. Tsuda, and N. Sasaki: e-J. Surf. Sci.

13㧕J. P. Lu, X.-P. Li, and R. M. Martin: Phys. Rev. Lett. 68,

3㧕 M. Ishikawa, R. Harada, N. Sasaki, and K. Miura: Phys.

14㧕S. D. Stoddard and J. Ford: Phys. Rev. A 8, 1504 (1973).

4㧕 N. Sasaki, H. Saitoh, K. Terada, N. Itamura, and K.

Flannery: Numerical Recipes : The Art of Scientific1551 (1992).

Nanotech.3, 21 (2005).

Rev. B80, 193406 (2009).

15㧕W. H. Press, S. A. Teukolsky, W. T. Vetterling, and B. P.

Computing (Cambridge Univ. Press, New York, 1992)

Miura: e-J. Surf. Sci. Nanotech. 7, 173 (2009).

2nd ed., 413.

5㧕 N. Sasaki, H. Okamoto, N. Itamura, and K. Miura: e-J.

㧙㧙