K. Takada

activity

20032006

most citedUnconventional Upper- and Lower-Critical Fields and Normal-State Magnetic Susceptibility of the Novel Superconducting Compound

N a_{0.35} C o O_{2} \cdot 1.3 H_{2} O

73 citations · 429 across the 15 of their papers we have counts for

collaborators

15 papers

cond-mat.supr-con2006★ 24 cited

Unconventional Superconductivity Induced by Quantum Critical Fluctuations in Hydrate Cobaltate Na $_{x}$ (H $_{3}$ O) $_{z}$ CoO $_{x} \cdot$ $y$ H $_{2}$ O -- Relationship between Magnetic Fluctuations and the Superconductivity Revealed by a Co Nuclear Quadrupole Resonance --

Y. Ihara, H. Takeya, K. Ishida +7

Co nuclear-quadrupole-resonance (NQR) measurements were performed on various bilayered hydrate cobaltate Na_x(H_3O)_zCoO_2\cdot yH_2O with different values of the superconducting a…

cond-mat.supr-con2005★ 22 cited

Anisotropic Behavior of Knight Shift in Superconducting State of Na_xCoO_2yH_2O

Y. Ihara, K. Ishida, H. Takeya +8

The Co Knight shift was measured in an aligned powder sample of Na_xCoO_2yH_2O, which shows superconductivity at T_c \sim 4.6 K. The Knight-shift components parallel (K_c) and perp…

cond-mat.supr-con2005★ 41 cited

Valence and Na content dependences of superconductivity in NaxCoO2.yH2O

H. Sakurai, N. Tsujii, O. Suzuki +5

Various samples of sodium cobalt oxyhydrate with relatively large amounts of Na $^{+}$ ions were synthesized by a modified soft-chemical process in which a NaOH aqueous solution was…

cond-mat.supr-con2005★ 8 cited

Superconducting phase diagram of NaxCoO2.yH2O

H. Sakurai, K. Takada, T. Sasaki +1

We synthesized Nax(H3O)zCoO2yH2O samples with various Na/H3O ratios but with the constant Co valence of s = +3.40, and measured their magnetic properties to draw phase diagrams of…

cond-mat.supr-con2005★ 1 cited

$^{23}$ Na NMR Study of Layered Superconductor $N a_{x} C o O_{2} - y H_{2} O$

H. Ohta, C. Michioka, Y. Itoh +5

We measured $^{23}$ Na-NMR spectra and nuclear spin-lattice relaxation rates $^{23} (1/ T_{1})$ of superconducting and non-superconducting bilayer hydrate $N a_{x} C o O_{2} - y H_{2} O$ (x ~ 0.3, y…

cond-mat.supr-con2005★ 23 cited

$^{17}$ O NMR Measurements on Superconducting Na $_{0.35}$ CoO $_{2} \cdot y$ H $_{2}$ O

Yoshihiko Ihara, Kenji Ishida, Kazuyoshi Yoshimura +4

An $^{17}$ O NMR measurement was performed on nonoriented polycrystalline Na $_{0.35}$ CoO $_{2} \cdot y$ H $_{2}$ O with superconducting (SC) transition temperature $T_{c} = 4.6$ K. A w…

Unconventional Superconductivity Induced by Quantum Critical Fluctuations in Hydrate Cobaltate Nax​(H3​O)z​CoOx​⋅ yH2​O -- Relationship between Magnetic Fluctuations and the Superconductivity Revealed by a Co Nuclear Quadrupole Resonance --