High-temperature thermoelectric properties of NaxCoO2-δ single crystals

被引：353

作者：

Fujita, K ^{[1
]}

Mochida, T ^{[1
]}

Nakamura, K ^{[1
]}

机构：

[1] Tokyo Gas Co Ltd, Frontier Technol Lab, Turumi Ku, Yokohama, Kanagawa 2300045, Japan

来源：

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS | 2001年 / 40卷 / 07期

关键词：

thermoelectrics; resistivity; thermoelectric power; thermal conductivity; power factor; figure-of-merit; sodium cobalt oxide;

D O I：

10.1143/JJAP.40.4644

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We measure the high-temperature thermoelectric properties of the NaxCoO2-delta single crystal for the first time. The NaxCoO2-delta single crystals are prepared by a flux technique, and the resulting flaky single crystals are very thin on the c-axis. The inplane electrical resistivity (rho), the thermoelectric power (S) and the in-plane thermal conductivity (kappa) are measured in the range of 300K to 800K. The estimated power factor (PF = S-2.rho (-1)) and the figure-of-merit (Z = S-2.rho (-1)kappa (-1)) are about 2.4mW m(-1) K-2 and 0.12 mK(-1) at 300K, respectively. These factors increase with temperature, and reach the value of PF = 7.7 mW m(-1) K-2 and Z = 1.5 mK(-1) at 800 K, and the dimensionless value of ZT exceeds the criterion of 1. The PF and Z exceed the values of typical "high-temperature thermoelectric materials", such as p-type FeSi2 and Si0.7Ge0.3. These results suggest that NaxCoO2-delta could be a very promising material for use in high-temperature thermoelectric power generation devices.

引用

页码：4644 / 4647

页数：4

共 23 条

[1] Specific-heat evidence for strong electron correlations in the thermoelectric material (Na,Ca) Co2O4 [J].

Ando, Y ;

Miyamoto, N ;

Segawa, K ;

Kawata, T ;

Terasaki, I .

PHYSICAL REVIEW B, 1999, 60 (15) :10580-10583

[2] Thermoelectric effect in a layered superconductor [J].

Belashchenko, KD ;

Livanov, DV .

JOURNAL OF LOW TEMPERATURE PHYSICS, 1996, 102 (1-2) :95-101

[3] THERMAL + ELECTRICAL PROPERTIES OF HEAVILY DOPED GE-SI ALLOYS UP TO 1300 DEGREES K [J].

DISMUKES, JP ;

EKSTROM, E ;

BEERS, DS ;

STEIGMEIER, EF ;

KUDMAN, I .

JOURNAL OF APPLIED PHYSICS, 1964, 35 (10) :2899-&

[4]

Fujiwara K, 1999, JAPAN INSTITUTE OF METALS, PROCEEDINGS, VOL 12, (JIMIC-3), PTS 1 AND 2, P481

[5] An oxide single crystal with high thermoelectric performance in air [J].

Funahashi, R ;

Matsubara, I ;

Ikuta, H ;

Takeuchi, T ;

Mizutani, U ;

Sodeoka, S .

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 2000, 39 (11B) :L1127-L1129

[6] THERMAL-DIFFUSIVITY MEASUREMENT OF THIN-FILMS BY MEANS OF AN AC CALORIMETRIC METHOD [J].

HATTA, I ;

SASUGA, Y ;

KATO, R ;

MAESONO, A .

REVIEW OF SCIENTIFIC INSTRUMENTS, 1985, 56 (08) :1643-1647

[7] NOTICE ON OXOCOBALTATES OF SODIUM [J].

JANSEN, M ;

HOPPE, R .

ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE, 1974, 408 (02) :104-106

[8] Ferroelectricity of Bi2SrTa2O9 single crystals grown by the self-flux method [J].

Machida, A ;

Nagasawa, N ;

Ami, T ;

Suzuki, M .

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 1997, 36 (12A) :7267-7271

[9] Low-temperature thermoelectric properties of the composite crystal [Ca2CoO3.34]0.614[CoO2] [J].

Miyazaki, Y ;

Kudo, K ;

Akoshima, M ;

Ono, Y ;

Koike, Y ;

Kajitani, T .

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 2000, 39 (6A) :L531-L533

[10] TRANSPORT-PROPERTIES OF NAXCOO2-Y [J].

MOLENDA, J ;

DELMAS, C ;

DORDOR, P ;

STOKLOSA, A .

SOLID STATE IONICS, 1984, 12 (MAR) :473-477

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