Skip to main content
SpringerLink
Log in

Tunneling spectroscopy of layered superconductors: intercalated Li0.48(C4H8O)xHfNCl and De-intercalated HfNCl0.7

  • Solid State and Materials
  • Published:
The European Physical Journal B Aims and scope Submit manuscript

Abstract

Tunneling measurements have been carried out on layered superconductors of the β(SmSI)-type – Li0.48(THF)xHfNCl (THF = C4H8O) and HfNCl0.7 – by means of break-junction and scanning tunneling spectroscopy. Break-junction technique reveals Bardeen-Cooper-Schrieffer (BCS) – like gap structures with typical gap values of 2Δ (4.2 K) = 11–12 meV for Li0.48(THF)xHfNCl with the highest Tc = 25.5 K. Some of our measurements revealed multiple gaps and dip-hump structures, the largest gap 2Δ (4.2 K) ≈ 17–20 meV closing at Tc. This was shown both by break-junction and scanning-tunneling spectroscopy. From these experiments it stems that the highest obtained gap ratio 2Δ/kBTc ~ 8 substantially exceeds the BCS weak-coupling limiting values: ≈3.5 and ≈4.3 for s-wave and d-wave order parameter symmetry, respectively. Such large 2Δ/kBTc ratios are rather unusual for conventional superconductors but quite common to high-Tc cuprates, as well as to organic superconductors. Our studies allowed to collect much more evidence concerning the huge pairing energy in those materials and to investigate in detail the complexity of their superconducting gap spectra. An origin of the observed phenomena still remains to be clarified.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • J. Nagamatsu, N. Nakagawa, T. Muranaka, Y. Zenitani, J. Akimitsu, Nature 410, 63 (2001)

    Google Scholar 

  • X.X. Xi, Rep. Prog. Phys. 71, 116501 (2008)

    Google Scholar 

  • G. Amano, S. Akutagawa, T. Muranaka, Y. Zenitani, J. Akimitsu, J. Phys. Soc. Jpn 73, 530 (2004)

    Google Scholar 

  • H. Takahashi, K. Igawa, K. Arii, Y. Kamihara, M. Hirano, H. Hosono, Nature 453, 376 (2008)

    Google Scholar 

  • H. Hosono, J. Phys. Soc. Jpn (Suppl C) 77, 1 (2008)

    Google Scholar 

  • M. Rotter, M. Tegel, D. Johrendt, Phys. Rev. Lett. 101, 107006 (2008)

    Google Scholar 

  • M.V. Sadovskii, Uspekhi Fiz. Nauk 178, 1243 (2008)

    Google Scholar 

  • A.L. Ivanovskii, Uspekhi Fiz. Nauk 178, 1273 (2008)

    Google Scholar 

  • Yu. A. Izyumov, E.Z. Kurmaev, Uspekhi Fiz. Nauk 178, 1307 (2008)

  • I.M. Chapnik, Phys. Lett. A 109, 69 (1985)

    Google Scholar 

  • J.K. Hulm, B.T. Matthias, Science 208, 881 (1980)

    Google Scholar 

  • M.L. Kulić, Phys. Rep. 338, 1 (2000)

    Google Scholar 

  • S. Maekawa, T. Tohyama, Rep. Prog. Phys. 64, 383 (2001)

    Google Scholar 

  • R.S. Markiewicz, J. Phys. Chem. Solids 58, 1179 (1997)

  • D.J. Scalapino, Phys. Rep. 250, 329 (1995)

    Google Scholar 

  • A. Bianconi, J. Supercond. 18, 625 (2005)

    Google Scholar 

  • N. Kristoffel, P. Konsin, T. Örd, Riv. Nuovo Cimento 17, 1 (1994)

    Google Scholar 

  • I.R. Shein, V.L. Kozhevnikov, A.L. Ivanovskii, Phys. Rev. B 78, 104519 (2008)

    Google Scholar 

  • M.M. Korshunov, I. Eremin, Phys. Rev. B 78, 140509 (2008)

    Google Scholar 

  • Yu. G. Naidyuk, I.K. Yanson, O.E. Kvitnitskaya, S. Lee, S. Tajima, Phys. Rev. Lett. 90, 197001 (2003)

    Google Scholar 

  • T. Takasaki, T. Ekino, R.A. Ribeiro, T. Muranaka, H. Fujii, J. Akimitsu, Physica C 426–431, 300 (2005)

  • Q. Han, Y. Chen, Z.D. Wang, EPL 82, 37007 (2008)

    Google Scholar 

  • S. Yamanaka, K. Hotehama, H. Kawaji, Nature 392, 580 (1998)

    Google Scholar 

  • S. Yamanaka, Annu. Rev. Mater. Sci. 30, 53 (2000)

    Google Scholar 

  • C. Felser, R. Seshadri, J. Mater. Chem. 9, 459 (1999)

    Google Scholar 

  • I. Hase, Y. Nishihara, Phys. Rev. B 60, 1573 (1999)

    Google Scholar 

  • I. Hase, Y. Nishihara, Physica B 281–282, 788 (2000)

  • H. Tou, Y. Maniwa, K. Ito, S. Yamanaka, Physica C 341–348, 2139 (2000)

    Google Scholar 

  • T. Ito, Y. Fudamoto, A. Fukaya, I.M. Gat-Malureanu, M.I. Larkin, P.L. Russo, A. Savici, Y.J. Uemura, K. Groves, R. Breslow, K. Hotehama, S. Yamanaka, P. Kyriakou, M. Rovers, G.M. Luke, K.M. Kojima, Phys. Rev. B 69, 134522 (2004)

  • T. Yokoya, Y. Ishiwata, S. Shin, S. Shamoto, K. Iizawa, T. Kajitani, I. Hase, T. Takahashi, Phys. Rev. B 64, 153107 (2001)

    Google Scholar 

  • L. Zhu, S. Yamanaka, Chem. Mater. 15, 1897 (2003)

    Google Scholar 

  • H. Tou, Y.J. Tanaka, M. Sera, Y. Taguchi, T. Sasaki, Y. Iwasa, L. Zhu, S. Yamanaka, Phys. Rev. B 72, R020501 (2005)

  • Y. Taguchi, M. Hisakabe, Y. Iwasa, Phys. Rev. Lett. 94, 217002 (2005)

  • T. Takasaki, T. Ekino, H. Fujii, S. Yamanaka, J. Phys. Soc. Jpn 74, 2586 (2005)

    Google Scholar 

  • E.L. Wolf, Principles of Electron Tunneling Spectroscopy (Oxford University Press, New York, 1985)

  • T. Ekino, S. Hashimoto, T. Takasaki, H. Fujii, Phys. Rev. B 64, 092510 (2001)

    Google Scholar 

  • T. Arai, K. Ichimura, K. Nomura, S. Takasaki, J. Yamada, S. Nakatsuji, H. Anzai, Phys. Rev. B 63, 104518 (2001)

    Google Scholar 

  • A. Damascelli, Z. Hussain, Z.-X. Shen, Rev. Mod. Phys. 75, 473 (2003)

  • J.C. Phillips, A. Saxena, A.R. Bishop, Rep. Prog. Phys. 66, 2111 (2003)

  • J.B. Goodenough, J. Phys.: Condens. Matter 15, R257 (2003)

  • Ø. Fischer, M. Kugler, I. Maggio-Aprile, C. Berthod, Rev. Mod. Phys. 79, 353 (2007)

  • H. Tou, Y. Maniwa, S. Yamanaka, Phys. Rev. B 67, R100509 (2003)

  • Y. Taguchi, T. Kawabata, T. Takano, A. Kitora, K. Kato, M. Takata, Y. Iwasa, Phys. Rev. B 76, 064508 (2007)

    Google Scholar 

  • W.L. McMillan, Phys. Rev. 167, 331 (1968)

    Google Scholar 

  • Y. Taguchi, M. Hisakabe, Y. Ohishi, S. Yamanaka, Y. Iwasa, Phys. Rev. B 70, 104506 (2004)

    Google Scholar 

  • T. Ekino, T. Takabatake, H. Tanaka, H. Fujii, Phys. Rev. Lett. 75, 4262 (1995)

    Google Scholar 

  • T. Ekino, H. Fujii, M. Kosugi, Y. Zenitani, J. Akimitsu, Phys. Rev. B 53, 5640 (1996)

    Google Scholar 

  • J.T. Okada, T. Ekino, T. Takasaki, Y. Yokoyama, Y. Watanabe, H. Fujii, S. Nanao, J. Non-Cryst. Solids 312–314, 513 (2002)

    Google Scholar 

  • J.T. Okada, T. Ekino, Y. Yokoyama, T. Takasaki, Y. Watanabe, S. Nanao, J. Phys. Soc. Jpn 76, 033707 (2007)

  • T. Ekino, A.M. Gabovich, M.S. Li, M. Pękała, H. Szymczak, A.I. Voitenko, J. Phys.: Condens. Matter 20, 425218 (2008)

  • R.C. Dynes, V. Narayanamurti, J.P. Garno, Phys. Rev. Lett. 41, 1509 (1978)

    Google Scholar 

  • W.A. Harrison, Phys. Rev. 123, 85 (1961)

    Google Scholar 

  • M.H. Cohen, L.M. Falicov, J.C. Phillips, Phys. Rev. Lett. 8, 316 (1962)

    Google Scholar 

  • D.H. Douglass, Jr., L.M. Falicov, Progr. Low Temp. Phys. 4, 97 (1964)

  • G.D. Mahan, Many-Particle Physics (Kluwer, New York, 2000)

  • J. Bardeen, Phys. Rev. Lett. 6, 57 (1961)

    Google Scholar 

  • V. Ambegaokar, A. Baratoff, Phys. Rev. Lett. 10, 486 (1963)

    Google Scholar 

  • I.O. Kulik, I.K. Yanson, Josephson Effect in Superconducting Tunnel Structures (Israel Program for Scientific Translation, Jerusalem, 1972)

  • L.Y.L. Shen, N.M. Senozan, N.E. Phillips, Phys. Rev. Lett. 14, 1025 (1965)

    Google Scholar 

  • L.Y.L. Shen, Phys. Rev. Lett. 29, 1082 (1972)

    Google Scholar 

  • S.I. Vedeneev, A.I. Golovashkin, G.P. Motulevich, Trudy FIAN SSSR 86, 140 (1975)

    Google Scholar 

  • J.R. Kirtley, R.M. Feenstra, A.P. Fein, S.I. Raider, W.J. Gallagher, R. Sandstrom, T. Dinger, M.W. Shafer, R. Koch, R. Laibowitz, B Bumble, J. Vac. Sci. Technol. A 6, 259 (1988)

    Google Scholar 

  • J.R. Kirtley, Int. J. Mod. Phys. B 4, 201 (1990)

    Google Scholar 

  • B. Barbiellini, Ø. Fischer, M. Peter, Ch. Renner, M. Weger, Physica C 220, 55 (1994)

  • H. Suhl, B.T. Matthias, L.R. Walker, Phys. Rev. Lett. 3, 552 (1959)

  • V.A. Moskalenko, Fiz. Metallov I Metalloved 8, 503 (1959) (in Russian)

  • A.M. Gabovich, E.A. Pashitskii, Ukrain. Fiz. Zhourn. 20, 1814 (1975) (in Russian)

  • A. Bussmann-Holder, L. Genzel, A. Simon, A.R. Bishop, Z. Phys. B 92, 149 (1993)

    Google Scholar 

  • P.W. Anderson, J. Phys. Chem. Sol. 11, 26 (1959)

    Google Scholar 

  • V.L. Pokrovsky, M.S. Ryvkin, Zh. Eksp. Teor. Fiz. 43, 92 (1962)

  • D.W. Youngner, R.A. Klemm, Phys. Rev. B 21, 3890 (1980)

    Google Scholar 

  • S.V. Pokrovsky, V.L. Pokrovsky, Phys. Rev. B 54, 13275 (1996)

    Google Scholar 

  • M.B. Walker, Phys. Rev. B 64, 134515 (2001)

    Google Scholar 

  • A.M. Gabovich, A.I. Voitenko, Phys. Rev. B 60, 7465 (1999)

    Google Scholar 

  • A.M. Gabovich, Mai Suan Li, M. Pękała, H. Szymczak, A.I. Voitenko, Physica C 405, 187 (2004)

    Google Scholar 

  • T. Ekino, A.M. Gabovich, Mai Suan Li, T. Takasaki, A.I. Voitenko, J. Akimitsu, H. Fujii, T. Muranaka, M. Pękała, H. Szymczak, Physica C 426–431, 230 (2005)

  • Z. Long, M.D. Stewart, Jr., T. Kouh, J.M. Valles, Jr., Phys. Rev. Lett. 93, 257001 (2004)

    Google Scholar 

  • Ya. G. Ponomarev, E.B. Tsokur, M.V. Sudakova, S.N. Tchesnokov, M.E. Shabalin, M.A. Lorenz, M.A. Hein, G. Müller, H. Piel, B.A. Aminov, Solid State Communs. 111, 513 (1999)

  • N.R. Werthamer, Phys. Rev. 147, 255 (1966)

    Google Scholar 

  • J.R. Schrieffer, J.W. Wilkins, Phys. Rev. Lett. 10, 17 (1963)

    Google Scholar 

  • M. Tachiki, S. Takahashi, F. Steglich, H. Adrian, Zeit. Physik 80, 161 (1990)

    Google Scholar 

  • T.G. Miller, M. McElfresh, R. Reifenberger, Phys. Rev. B 48, 7499 (1993)

  • K.K. Likharev, Rev. Mod. Phys. 51, 101 (1979)

    Google Scholar 

  • E.L. Nagaev, Uspekhi Fiz. Nauk 165, 529 (1995)

    Google Scholar 

  • E.V.L. de Mello, E.S. Caixeiro, Phys. Rev. B 70, 224517 (2004)

    Google Scholar 

  • T. Ekino, A.M. Gabovich, Mai Suan Li, M. Pękała, H. Szymczak, A.I. Voitenko, Phys. Rev. B 76, 180503 (2007)

    Google Scholar 

  • Ch. Renner, Ø. Fischer, Phys. Rev. B 51, 9208 (1995)

    Google Scholar 

  • A. Gilabert, J.P. Romagnan, E. Guyon, Solid State Commun. 9, 1295 (1971)

  • T. Ekino, T. Takasaki, T. Muranaka, J. Akimitsu, H. Fujii, Phys. Rev. B 67, 094504 (2003)

    Google Scholar 

  • T. Takasaki, T. Ekino, T. Muranaka, T. Ichikawa, H. Fujii, J. Akimitsu, J. Phys. Soc. Jpn 73, 1902 (2004)

    Google Scholar 

  • P. Raychaudhuri, D. Jaiswal-Nagar, G. Sheet, S. Rarnakrishnan, H. Takeya, Phys. Rev. Lett. 93, 156802 (2004)

  • T. Ekino, T. Takasaki, H. Fujii, S. Yamanaka, Physica C 388–389, 573 (2003)

    Google Scholar 

  • N.A. Belous, A.M. Gabovich, I.V. Lezhnenko, D.P. Moiseev, V.M. Postnikov, S.K. Uvarova, Phys. Lett. A 92, 455 (1982)

    Google Scholar 

  • N.A. Belous, A.E. Chernyakhovskii, A.M. Gabovich, D.P. Moiseev, V.M. Postnikov, J. Phys. C: Solid State Phys. 21, L153 (1988)

  • Y. Enomoto, M. Suzuki, T. Murakami, T. Inukai, T. Inamura, Jpn. J. Appl. Phys. 20, L661 (1981)

  • M. Suzuki, Y. Enomoto, T. Murakami, J. Appl. Phys. 56, 2083 (1984)

  • V.M. Krasnov, A. Yurgens, D. Winkler, P. Delsing, T. Claeson, Phys. Rev. Lett. 84, 5860 (2000)

    Google Scholar 

  • A.A. Yurgens, Supercond. Sci. Technol. 13, R85 (2000)

  • A. Yurgens, M. Torstensson, L.X. You, T. Bauch, D. Winkler, I. Kakeya, K. Kadowaki, Physica C 468, 674 (2008)

    Google Scholar 

  • M. Suzuki, T. Watanabe, Phys. Rev. Lett. 85, 4787 (2000)

    Google Scholar 

  • G.M. Eliashberg, Zh. Eksp. Teor. Fiz. 38, 966 (1960)

  • G.M. Eliashberg, Zh. Eksp. Teor. Fiz. 39, 1437 (1960)

  • B.T. Geilikman, V.Z. Kresin, N.F. Masharov, J. Low Temp. Phys. 18, 241 (1975)

    Google Scholar 

  • P.B. Allen, B. Mitrović, Solid State Phys. 37, 1 (1982)

    Google Scholar 

  • J.P. Carbotte, Rev. Mod. Phys. 62, 1027 (1990)

    Google Scholar 

  • D. Kondepudi, I. Prigogine, Modern Thermodynamics. From Heat Engines to Dissipative Structures (John Wiley and Sons, Chichister, 1999)

  • F. Marsiglio, J.P. Carbotte, Phys. Rev. B 33, 6141 (1986)

    Google Scholar 

  • A. Cros, A. Cantarero, D. Beltran-Porter, J. Oro-Sole, A. Fuertes, Phys. Rev. B 67, 104502 (2003)

  • P. Adelmann, B. Renker, H. Schober, M. Braden, F. Fernandez-Diaz, J. Low. Temp. Phys. 117, 449 (1999)

    Google Scholar 

  • S. Shamoto, K. Iizawa, T. Koiwasaki, M. Yasukawa, S. Yamanaka, O. Petrenko, S.M. Bennington, H. Yoshida, K. Ohoyama, Y. Yamaguchi, Y. Ono, Y. Miyazaki, T. Kjitani, Physica C 341–348, 747 (2000)

  • N. Tsuda, Private communications

  • R. Heid, K.–P. Bohnen, Phys. Rev. B 72, 134527 (2005)

    Google Scholar 

  • K. Kuroki, S. Onari, R. Arita, H. Usui, Y. Tanaka, H. Kontani, H. Aoki, Phys. Rev. Lett. 101, 087004 (2008)

    Google Scholar 

  • K. Kuroki, Sci. Technol. Adv. Mater. 9, 044202 (2008)

    Google Scholar 

  • E.A. Pashitskii, Yu. A Romanov, Ukrain. Fiz. Zhourn. 15, 1594 (1970) (in Russian)

  • Y. Takada, J. Phys. Soc. Jpn 45, 786 (1978)

    Google Scholar 

  • A. Bill, H. Morawitz, V.Z. Kresin, Phys. Rev. B 66, R100501 (2002)

  • S. Yamanaka, K. Hotehama, T. Koiwasaki, H. Kawaji, H. Fukuoka, S. Shamoto, T. Kawajiri, Physica C 341–348, 699 (2000)

  • A. Kitora, Y. Taguchi, Y. Iwasa, J. Phys. Soc. Jpn 76, 023706 (2007)

  • K.M. Lang, V. Madhavan, J.E. Hoffman, E.W. Hudson, H. Eisaki, S. Uchida, J.C. Davis, Nature 415, 412 (2002)

  • A.A. Abrikosov, Modern Thermodynamics. Fundamentals of the Theory of Metals (North-Holland, Amsterdam, 1987)

  • H. Won, K. Maki, Phys. Rev. B 49, 1397 (1994)

    Google Scholar 

  • A.S. Alexandrov, J. Phys: Condensed Matter 19, 125216 (2007)

Download references

Author information

Authors and Affiliations

  1. Graduate school of Advanced Sciences of Matter, Hiroshima University, 739-8530, Higashi-Hiroshima, Japan

    T. Takasaki

  2. Graduate school of Integrated Arts and Sciences, Hiroshima University, 739-8521, Higashi-Hiroshima, Japan

    T. Ekino, A. Sugimoto & K. Shohara

  3. Graduate school of Engineering, Hiroshima University, 739-8527, Higashi-Hiroshima, Japan

    S. Yamanaka

  4. Institute of Physics of the National Academy of Sciences, Nauka Avenue 46, 03680, Kiev, Ukraine

    A. M. Gabovich

Authors
  1. T. Takasaki
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. T. Ekino
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. Sugimoto
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. K. Shohara
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. S. Yamanaka
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. A. M. Gabovich
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to T. Ekino.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Takasaki, T., Ekino, T., Sugimoto, A. et al. Tunneling spectroscopy of layered superconductors: intercalated Li0.48(C4H8O)xHfNCl and De-intercalated HfNCl0.7 . Eur. Phys. J. B 73, 471–482 (2010). https://doi.org/10.1140/epjb/e2010-00035-4

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1140/epjb/e2010-00035-4

Keywords

Search

Navigation