Anomalous thermopower of the electron-doped superconductor, SM2-xCexCuO4

被引:5
作者
Yang, HS [1 ]
Chai, YS [1 ]
Liu, J [1 ]
Yu, M [1 ]
Li, PC [1 ]
Zhang, L [1 ]
Li, MD [1 ]
Cao, LZ [1 ]
机构
[1] Univ Sci & Technol China, Dept Phys, Struct Res Lab, Anhua 230026, Peoples R China
来源
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS | 2004年 / 403卷 / 03期
关键词
transport properties; cuprate superconductor; thermoelectric power;
D O I
10.1016/j.physc.2003.12.012
中图分类号
O59 [应用物理学];
学科分类号
摘要
The thermopower of Sm2-xCexCuO4 single crystal (x = 0. 15) and polycrystalline samples (0.06 less than or equal to x less than or equal to 0.21) has been measured. The positive slope in thermopower in the underdoped region emphasizes the existence of a high temperature regime above 200 K or so where only including the Fermi liquid model is not satisfactory. The high temperature thermopower suggests that a competition exists between the electron-type (energy band) band and hole-type (polaron band) band contributions. The crossover of charge carriers from hole-type to electron-type happens at x = 0.17. The changes of slopes in the thermopower below about 200 K are attributed to the opening of a pseudogap in the underdoped region and the localization of electrons in the energy band in the overdoped region. A positive phonon-drag contribution for thermopower near 50 K is observed, indicating that the signs of the carriers are positive at low temperature. (C) 2003 Elsevier B.V. All rights reserved.
引用
收藏
页码:203 / 208
页数:6
相关论文
共 24 条
[21]   A SUPERCONDUCTING COPPER-OXIDE COMPOUND WITH ELECTRONS AS THE CHARGE-CARRIERS [J].
TOKURA, Y ;
TAKAGI, H ;
UCHIDA, S .
NATURE, 1989, 337 (6205) :345-347
[22]   THERMOELECTRIC-POWER OF ND2-XCEX CUO4 CRYSTALS [J].
XU, XQ ;
HAGEN, SJ ;
JIANG, W ;
PENG, JL ;
LI, ZY ;
GREENE, RL .
PHYSICAL REVIEW B, 1992, 45 (13) :7356-7359
[23]   Investigating the pairing state of cuprate superconductors via quasiparticle tunneling and spin injection [J].
Yeh, NC ;
Chen, CT ;
Fu, CC ;
Seneor, P ;
Huang, Z ;
Jung, CU ;
Kim, JY ;
Park, MS ;
Kim, HJ ;
Lee, SI ;
Yoshida, K ;
Tajima, S ;
Hammerl, G ;
Mannhart, J .
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 2002, 367 (1-4) :174-180
[24]   Anomalous thermopower and resistivity of the electron-doped superconductor Sm2-xCexCuO4 (0.00 ≤ x ≤ 0.21) [J].
Yu, M ;
Yang, HS ;
Chai, YS ;
Ruan, KQ ;
Li, PC ;
Li, ZQ ;
Chen, ZJ ;
Cao, LZ .
ACTA PHYSICA SINICA, 2002, 51 (03) :674-678