Soft X-ray Absorption and Photoemission Spectroscopy Study of Cobalt-Based Thermoelectric Oxides: Ca3Co4O9, Ca3Co2O6, and Bi2Sr2Co2Oy

被引：0

作者：

Kang, J. -S. ^{[1
]}

Lee, H. J. ^{[1
]}

Kim, D. H. ^{[1
]}

Fujii, T. ^{[2
]}

Terasaki, I. ^{[2
]}

Park, H. L. ^{[3
]}

Jeong, Y. H. ^{[3
]}

Min, B. I. ^{[3
]}

机构：

[1] Catholic Univ Korea, Dept Phys, Puchon 420743, South Korea

[2] Waseda Univ, Dept Appl Phys, Tokyo 1698555, Japan

[3] POSTECH, Dept Phys, Pohang 790784, South Korea

来源：

JOURNAL OF ELECTRONIC MATERIALS | 2009年 / 38卷 / 07期

关键词：

XAS; PES; electronic structure; thermopower; cobalt oxides; TRANSITION-METAL COMPOUNDS; MISFIT-LAYERED COBALTITE; SINGLE-CRYSTALS; THERMOPOWER; SYMMETRY; POWER;

D O I：

10.1007/s11664-008-0631-0

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

The electronic structures of Co-based potential thermoelectric (TE) oxides, including Ca3Co4O9 and Bi(2)Sr(2)Co(2)Oy (y = 8 + delta) single crystals and polycrystalline Ca3Co2O6, have been investigated by employing soft x-ray absorption spectroscopy (XAS) and photoemission spectroscopy (PES). Co 2p XAS measurements show that Co ions are nearly trivalent (Co3+) in all of these Co-based TE oxides with a small mixture of Co4+ ions in Bi2Sr2Co2Oy. Valence-band PES and O 1s XAS measurements show that the occupied Co 3d states are located at the top of the valence bands and that the lowest unoccupied states have the primarily Co 3d character, respectively. These findings suggest the importance of the Co 3d electronic structures in determining TE properties of these Co-based oxides.

引用

页码：1127 / 1131

页数：5

共 30 条

[11] Valence-band photoemission spectroscopy of the giant magnetoresistive spinel compound Fe0.5Cu0.5Cr2S4 -: art. no. 144412 [J].

Kang, JS ;

Kim, SJ ;

Kim, CS ;

Olson, CG ;

Min, BI .

PHYSICAL REVIEW B, 2001, 63 (14)

[12] Thermopower in cobalt oxides [J].

Koshibae, W ;

Tsutsui, K ;

Maekawa, S .

PHYSICAL REVIEW B, 2000, 62 (11) :6869-6872

[13] Effects of spin and orbital degeneracy on the thermopower of strongly correlated systems [J].

Koshibae, W ;

Maekawa, S .

PHYSICAL REVIEW LETTERS, 2001, 87 (23) :236603-1

[14]

Kuno S., 2007, P 2007 26 INT C THER, VVolume 2, P99

[15] Three forms of the misfit layered cobaltite [Ca2CoO3] [CoO2]1.62 -: A 4D structural investigation [J].

Lambert, S ;

Leligny, H ;

Grebille, D .

JOURNAL OF SOLID STATE CHEMISTRY, 2001, 160 (02) :322-331

[16] One dimensional compounds with large thermoelectric power:: Ca3Co2O6 and Ca3CoMO6 with M = Ir4+ and Rh4+ [J].

Maignan, A ;

Hébert, S ;

Martin, C ;

Flahaut, D .

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 2003, 104 (03) :121-125

[17] Misfit-layered cobaltite with an anisotropic giant magnetoresistance:: Ca3Co4O9 [J].

Masset, AC ;

Michel, C ;

Maignan, A ;

Hervieu, M ;

Toulemonde, O ;

Studer, F ;

Raveau, B ;

Hejtmanek, J .

PHYSICAL REVIEW B, 2000, 62 (01) :166-175

[18] 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

[19] X-ray absorption study of layered Co oxides with a Co-O triangular lattice [J].

Mizokawa, T ;

Tjeng, LH ;

Lin, HJ ;

Chen, CT ;

Kitawaki, R ;

Terasaki, I ;

Lambert, S ;

Michel, C .

PHYSICAL REVIEW B, 2005, 71 (19)

[20] Photoemission and x-ray-absorption study of misfit-layered (Bi,Pb)-Sr-Co-O compounds: Electronic structure of a hole-doped Co-O triangular lattice [J].

Mizokawa, T ;

Tjeng, LH ;

Steeneken, PG ;

Brookes, NB ;

Tsukada, I ;

Yamamoto, T ;

Uchinokura, K .

PHYSICAL REVIEW B, 2001, 64 (11)

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