Anisotropic behavior of knight shift in superconducting state of NaxCoO2•yH2O

被引：19

作者：

Ihara, Y ^{[1
]}

Ishida, K

Takeya, H

Michioka, C

Kato, M

Itoh, Y

Yoshimura, K

Takada, K

Sasaki, T

Sakurai, H

Takayama-Muromachi, E

机构：

[1] Kyoto Univ, Grad Sch Sci, Dept Phys, Kyoto 6068502, Japan

[2] Kyoto Univ, Grad Sch Sci, Dept Chem, Kyoto 6068502, Japan

[3] Natl Inst Mat Sci, Adv Mat Lab, Tsukuba, Ibaraki 3050044, Japan

[4] Natl Inst Mat Sci, Supercond Mat Ctr, Tsukuba, Ibaraki 3050044, Japan

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 2006年 / 75卷 / 01期

关键词：

superconductivity; hydrate sodium cobalt oxide; NMR; spin fluctuations;

D O I：

10.1143/JPSJ.75.013708

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The Co Knight shift was measured in an aligned powder sample of NaxCoO2 center dot yH(2)O, which shows superconductivity at T-c similar to 4.6 K. The Knight-shift components parallel (K-c) and perpendicular to the c-axis (along the ab plane K-ab) were measured in both the normal and superconducting (SC) states. The temperature dependences of K-ab and K-c are scaled with the bulk susceptibility, which shows that the microscopic susceptibility deduced from the Knight shift is related to Co-3d spins. In the SC state, the Knight shift shows an anisotropic temperature dependence: K-ab decreases below 5 K, whereas K-c does not decrease within experimental accuracy. This result raises the possibility that spin-triplet superconductivity with the spin component of the pairs directed along the c-axis is realized in NaxCoO2 center dot yH(2)O.

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页数：4

相关论文

共 23 条

[1] Thermodynamic and transport measurements of superconducting Na0.3CoO2•1.3H2O single crystals prepared by electrochemical deintercalation -: art. no. 157004 [J].

Chou, FC ;

Cho, JH ;

Lee, PA ;

Abel, ET ;

Matan, K ;

Lee, YS .

PHYSICAL REVIEW LETTERS, 2004, 92 (15) :157004-1

[2] Unconventional superconductivity and electron correlations in the cobalt oxyhydrate Na0.35CoO2•yH2O from nuclear quadrupole resonance -: art. no. 047004 [J].

Fujimoto, T ;

Zheng, GQ ;

Kitaoka, Y ;

Meng, RL ;

Cmaidalka, J ;

Chu, CW .

PHYSICAL REVIEW LETTERS, 2004, 92 (04) :4

[3] Possible unconventional superconductivity in NaxCoO2•yH2O probed by muon spin rotation and relaxation -: art. no. 134508 [J].

Higemoto, W ;

Ohishi, K ;

Koda, A ;

Saha, SR ;

Kadono, R ;

Ishida, K ;

Takada, K ;

Sakurai, H ;

Takayama-Muromachi, E ;

Sasaki, T .

PHYSICAL REVIEW B, 2004, 70 (13) :134508-1

[4] 17O NMR measurements on superconducting Na0.35CoO2•yH2O [J].

Ihara, Y ;

Ishida, K ;

Yoshimura, K ;

Takada, K ;

Sasaki, T ;

Sakura, H ;

Takayama-Muromachi, E .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2005, 74 (08) :2177-2180

[5] Weak magnetic order in bilayered-hydrate NaxCoO2•yH2O structure probed by Co nuclear quadrupole resonance -: Proposed phase diagram in superconducting NaxCoO2•yH2O- [J].

Ihara, Y ;

Ishida, K ;

Michioka, C ;

Kato, M ;

Yoshimura, K ;

Takada, K ;

Sasaki, T ;

Sakurai, H ;

Takayama-Muromachi, E .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2005, 74 (03) :867-870

[6] Correlation between superconducting transition temperature Tc and increase of nuclear spin-lattice relaxation rate devided by temperature 1/T1T at Tc in the hydrate cobaltate NaxCoO2•yH2O [J].

Ihara, Y ;

Ishida, K ;

Michioka, C ;

Kato, M ;

Yoshimura, K ;

Takada, K ;

Sasaki, T ;

Sakura, H ;

Takayama-Muromachi, E .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2004, 73 (08) :2069-2072

[7]

Ihara Y., UNPUB

[8] Possibility of f-wave spin-triplet superconductivity in the CoO2 superconductor:: A case study on a 2D triangular lattice in the repulsive Hubbard model [J].

Ikeda, H ;

Nisikawa, Y ;

Yamada, K .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2004, 73 (01) :17-20

[9] Unconventional superconductivity and nearly ferromagnetic spin fluctuations in NaxCoO2•γH2O [J].

Ishida, K ;

Ihara, Y ;

Maeno, Y ;

Michioka, C ;

Kato, M ;

Yoshimura, K ;

Takada, K ;

Sasaki, T ;

Sakurai, H ;

Takayama-Muromachi, E .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2003, 72 (12) :3041-3044

[10] Muon spin relaxation measurements of NaxCoO2 • yH2O -: art. no. 257007 [J].

Kanigel, A ;

Keren, A ;

Patlagan, L ;

Chashka, KB ;

King, P ;

Amato, A .

PHYSICAL REVIEW LETTERS, 2004, 92 (25) :257007-1