中国物理B ›› 1993, Vol. 2 ›› Issue (12): 930-936.doi: 10.1088/1004-423X/2/12/007

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THERMOELECTRIC POWER IN (Gd, Sm)1.85Ce0.15CuO4 SYSTEM

刘国良, 林征, 林勤, 张玉芬, 蒋连化, 李国红, 阎守胜   

  1. Department of Physics, Peking University, Beijing 100871, China
  • 收稿日期:1992-12-09 出版日期:1993-12-20 发布日期:1993-12-20
  • 基金资助:
    Project supported by the National Center for Research and Development on Superconductivity of China.

THERMOELECTRIC POWER IN (Gd, Sm)1.85Ce0.15CuO4 SYSTEM

LIU GUO-LIANG (刘国良), LIN-ZHENG (林征), LIN QIN (林勤), ZHANG YU-FEN (张玉芬), JIANG LIAN-HUA (蒋连化), LI GUO-HONG (李国红), YAN SHOU-SHENG (阎守胜)   

  1. Department of Physics, Peking University, Beijing 100871, China
  • Received:1992-12-09 Online:1993-12-20 Published:1993-12-20
  • Supported by:
    Project supported by the National Center for Research and Development on Superconductivity of China.

摘要: Thermoelectric power measurements are reported for seven samples with different x in the Gd1.85-xSmxCe0.15CuO4 system at temperatures ranging from 80K to 300K. For Sm-rich superconducting samples, thermoelectric power S has a small negative value and is almost temperature independent. As the content of Sm decreases, the absolute value of S increases and a broad valley appears in the S(T) curve. The results which can be interpreted in terms of a two-channel model support the existence of mid-gap states with Fermi level close to the minimum of the density of states as well as the coexistence of electron and hole carriers. It is suggested that a linear temperature dependence of S with a small negative slope is close to the intrinsic behavior in the a-b plane of normal states for superconducting samples.

Abstract: Thermoelectric power measurements are reported for seven samples with different x in the Gd1.85-xSmxCe0.15CuO4 system at temperatures ranging from 80K to 300K. For Sm-rich superconducting samples, thermoelectric power S has a small negative value and is almost temperature independent. As the content of Sm decreases, the absolute value of S increases and a broad valley appears in the S(T) curve. The results which can be interpreted in terms of a two-channel model support the existence of mid-gap states with Fermi level close to the minimum of the density of states as well as the coexistence of electron and hole carriers. It is suggested that a linear temperature dependence of S with a small negative slope is close to the intrinsic behavior in the a-b plane of normal states for superconducting samples.

中图分类号: 

  • 74.25.Fy
74.25.Jb (Electronic structure (photoemission, etc.))