Takada, Y., Nakanishi, M., Fujii, T., Takada, J., Muraoka, Y.
An ilmenite-hematite solid solution ( Fe2-xTixO3 ) is one of the candidates for practical magnetic semiconductors with a high Curie temperature. We have prepared well-crystallized epitaxial...
Koda, A., Kadono, R., Ohishi, K., Saha, S. R., Higemoto, W., Yonezawa, S., ...
We report on the muon spin rotation/relaxation study of a pyrochlore oxide, Cd2Os2O7, which exhibits a metal-insulator (MI) transition at T_{MI}~225 K without structural phase transition. It reveals...
Photoemission study of TiO2/VO2 interfaces (2006)
Maekawa, K., Takizawa, M., Wadati, H., Yoshida, T., Fujimori, A., Kumigashira, H., ...
We have measured photoemission spectra of two kinds of TiO$_2$-capped VO$_2$ thin films, namely, that with rutile-type TiO$_2$ (r-TiO$_2$/VO$_2$) and that with amorphous TiO$_2$ (a-TiO$_2$/VO$_2$)...
NMR Observation of Rattling Phonons in the Pyrochlore Superconductor KOs2O6 (2006)
Yoshida, M., Arai, K., Kaido, R., Takigawa, M., Yonezawa, S., Muraoka, Y., ...
We report nuclear magnetic resonance studies on the beta-pyrochlore oxide superconductor KOs2O6. The nuclear relaxation at the K sites is entirely caused by fluctuations of electric field gradient,...
Photoemission evidence for a Mott-Hubbard metal-insulator transition in VO$_2$ (2006)
Eguchi, R., Taguchi, M., Matsunami, M., Horiba, K., Yamamoto, K., Ishida, Y., ...
The temperature ($T$) dependent metal-insulator transition (MIT) in VO$_2$ is investigated using bulk sensitive hard x-ray ($\sim$ 8 keV) valence band, core level, and V 2$p-3d$ resonant...
Okazaki, K., Sugai, S., Muraoka, Y., Hiroi, Z.
We have investigated the charge dynamics of VO_2 by optical reflectivity measurements. Optical conductivity clearly shows a metal-insulator transition. In the metallic phase, a broad Drude-like...
Okazaki, K., Sugai, S., Muraoka, Y., Hiroi, Z.
We have investigated the charge dynamics of VO2 by optical reflectivity measurements. Optical conductivity clearly shows a metal-insulator transition. In the metallic phase, a broad Drude-like...
Kasahara, Y., Shimono, Y., Shibauchi, T., Matsuda, Y., Yonezawa, S., Muraoka, Y., ...
To elucidate the nature of the superconducting ground state of the geometrically frustrated pyrochlore KOs2O6 (Tc=9.6K), the thermal conductivity was measured down to low temperatures (~Tc/100). We...
Spin-1/2 triangular lattice with orbital degeneracy in a metallic oxide Ag2NiO2 (2006)
Yoshida, H., Muraoka, Y., Sörgel, T., Jansen, M., Hiroi, Z.
A metallic and magnetic transition metal oxide Ag2NiO2 is studied by means of resistivity, magnetic susceptibility, specific heat, and x-ray diffraction. The crystal structure is characterized by an...
Spin-1/2 Triangular Lattice with Orbital Degeneracy in a Metallic Oxide Ag2NiO2 (2005)
Yoshida, H., Muraoka, Y., Soergel, T., Jansen, M., Hiroi, Z.
A novel metallic and magnetic transition metal oxide Ag2NiO2 is studied by means of resistivity, magnetic susceptibility, specific heat and X-ray diffraction. The crystal structure is characterized...
High pressure effects on the superconductivity of beta-pyrochlore oxides AOs2O6 (2005)
Muramatsu, T., Takeshita, N., Terakura, C., Takagi, H., Tokura, Y., Yonezawa, S., ...
High pressure effects on the superconducting transitions of beta-pyrochlore superconductors AOs2O6 (A = Cs, Rb, K) are studied by measuring resistivity under high pressures up to 10 GPa. The...
39K and 87Rb Nuclear Magnetic Resonance in the Pyrochlore Superconductors AOs2O6 (A=K, Rb) (2004)
Arai, K., Kikuchi, J., Kodama, K., Takigawa, M., Yonezawa, S., Muraoka, Y., ...
This paper has been withdrawn by the authors, since a crucial assumption in the analysis of the data was found to be incorrect from the later experiments.
New Pyrochlore Oxide Superconductor RbOs2O6 (2004)
Yonezawa, S., Muraoka, Y., Matsushita, Y., Hiroi, Z.
We report the discovery of a new pyrochlore oxide superconductor RbOs2O6. The compound crystallizes in the same beta-pyrochlore structure as the recently discovered superconductor KOs2O6, where Os...
Koda, A., Higemoto, W., Ohishi, K., Saha, S. R., Kadono, R., Yonezawa, S., ...
Magnetic penetration depth ($\lambda$) in a pyrochlore superconductor KOs$_2$O$_6$ was studied by means of muon spin rotation (\msr). The temperature dependence of transverse spin relaxation rate,...
Unprecedented Superconductivity in the beta-Pyrochlore Osmate KOs2O6 (2004)
Hiroi, Z., Yonezawa, S., Muraoka, Y.
Superconductivity in the potassium osmium oxide KOs2O6 crystallizing in the beta-pyrochlore structure is studied by means of electrical resistivity, magnetic susceptibility and specific heat. It is...
Okazaki, K., Wadati, H., Fujimori, A., Onoda, M., Muraoka, Y., Hiroi, Z.
We have made a detailed temperature-dependent photoemission study of VO_2/TiO_2(001) thin films, which show a metal-insulator transition at \sim 300 K. Clean surfaces were obtained by annealing the...
Photocarrier Injection to Transition Metal Oxides (2003)
This paper has been withdrawn by the author(s), due a crucial error in the data.
Correlations and Semimetallic Behaviors in Pyrochlore Oxide Cd2Re2O7 (2002)
Hiroi, Z., Hanawa, M., Muraoka, Y., Harima, H.
Electronic properties of the metallic pyrochlore oxide Cd2Re2O7 are studied by means of electrical resistivity and Hall measurements. Semimetallic band structures are revealed as expected from band...
Structural Phase Transition in the Superconducting Pyrochlore Oxide Cd2Re2O7 (2001)
Hanawa, M., Yamaura, J., Muraoka, Y., Sakai, F., Hiroi, Z.
We report a structural phase transition found at Ts = 200 K in a pyrochlore oxide Cd2Re2O7 which shows superconductivity at Tc = 1.0 K. X-ray diffractionexperiments indicate that the phase transition...
Superconductivity at 1 K in Cd2Re2O7 (2001)
Hanawa, M., Muraoka, Y., Tayama, T., Sakakibara, T., Yamaura, J., Hiroi, Z.
We report the first pyrochlore oxide superconductor Cd2Re2O7. Resistivity,magnetic susceptibility,and specific heat measurements on single crystals evidence a bulk superconductivity at 1 K. Another...
MICTOMAGNETISM IN Zr(Fe-Co)2 (1979)
Muraoka, Y., Shiga, M., Nakamura, Y.
Magnetic and Mössbauer measurements have been made for the pseudobinary Zr(Fe1-xCox)2 system. Both measurements clearly show that mictomagnetism appears for x = 0.5 ~ 0.7, as ferromagnetism vanishes.
MICTOMAGNETISM IN Zr(Fe-Co)2 (1979)
Muraoka, Y., Shiga, M., Nakamura, Y.
Magnetic and Mössbauer measurements have been made for the pseudobinary Zr(Fe1-xCox)2 system. Both measurements clearly show that mictomagnetism appears for x = 0.5 ~ 0.7, as ferromagnetism vanishes.
MICTOMAGNETISM IN Zr(Fe-Co)2 (1979)
Muraoka, Y., Shiga, M., Nakamura, Y.
Magnetic and Mössbauer measurements have been made for the pseudobinary Zr(Fe1-xCox)2 system. Both measurements clearly show that mictomagnetism appears for x = 0.5 ~ 0.7, as ferromagnetism vanishes.
Ishihara, M, Sato, H, Tateishi, H, Kawagoe, T, Yoshimura, M, Muraoka, Y
OBJECTIVE--To examine coronary flow reserve immediately after emergency coronary angioplasty in patients with acute myocardial infarction. DESIGN--A 3 F coronary Doppler catheter was used to measure...