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Calorimetric study of molecular superconductor κ-(BEDT-TTF)2Ag(CN)2H2O which contains water in the anion layers

  • T. Ishikawa
  • S. Yamashita
  • Y. Nakazawa
  • A. Kawamoto
  • M. Oguni
Article

Abstract

Thermodynamic investigation of an organic superconductor κ-(BEDT-TTF)2Ag(CN)2H2O in which the BEDT-TTF dimers are arranged in the κ-type structure in the donor layers is performed by the relaxation calorimetric technique at low temperatures and under magnetic fields. A thermal anomaly related to the superconductive phase transition was observed at 5 K. The existence of residual γ* in the superconductive state is about 18% of the normal state γ value, which is larger than those of κ-(BEDT-TTF)2Cu(NCS)2, and κ-(BEDT-TTF)2Cu[N(CN)2]Br salt. The lattice heat capacity reflected on the β-term in the low-temperature heat capacity was found to be affected by the cooling rate. The disorder produced in the network structure constructed by hydrogen bond in the insulating layer is considered to give low-energy phonon excitations reflected in the heat capacity.

Keywords

electronic heat capacity coefficient organic superconductor strongly correlated electrons system relaxation calorimetry 

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Copyright information

© Springer Science+Business Media, LLC. 2008

Authors and Affiliations

  • T. Ishikawa
    • 1
  • S. Yamashita
    • 2
  • Y. Nakazawa
    • 2
    • 3
  • A. Kawamoto
    • 4
  • M. Oguni
    • 1
  1. 1.Department of ChemistryTokyo Institute of TechnologyMeguro-Ku, TokyoJapan
  2. 2.Department of ChemistryOsaka UniversityToyonaka, OsakaJapan
  3. 3.CREST-JSTHoncho, Kawaguchi, SaitamaJapan
  4. 4.Department of PhysicsHokkaido UniversitySapporo, HokkaidoJapan

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