Journal of Superconductivity

, Volume 7, Issue 1, pp 1–7 | Cite as

Superconductivity at higher temperatures in the Hg-Ba-Ca-Cu-O compound system

  • C. W. Chu
I. New System

Abstract

Our recent systematic examination of the pressure effect on high-temperature superconductors revealed that the highest achievable superconducting transition temperature (Tc) in the layered cuprates may lie between ∼150 and ∼180 K. We propose that the newly discovered Hg-Ba-Ca-Cu-O (HBCCO) compound system may be one of the most promising candidates for such a high-Tc superconductor, because of the possible large range of modulation doping associated with the linear oxygen coordination of divalent Hg in HBCCO. A record-high magnetically determined transition at 135 K with a zero resistivity at 134 K has been obtained by us in HgBa2Ca2Cu3O8+δ. TheTc of HgBa2Ca2Cu3O8+δ was found to increase continuously with pressure at an increasing rate up to ∼17 kbar without any sign of saturation. The thermo-power shows an underdoped characteristic. These observations suggest that theTc of HBCCO can be further enhanced with proper modulation doping without inducing any structural instabilities. The results together with the synthesis steps of HBCCO are summarized and discussed.

Key words

High-temperature superconductivity compound synthesis pressure effect 

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Copyright information

© Plenum Publishing Corporation 1994

Authors and Affiliations

  • C. W. Chu
    • 1
  1. 1.Department of Physics and Texas Center for SuperconductivityUniversity of HoustonHouston

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