Y. Uwatoko

Publication List Details

Period

1988 - 2008

Number

30

Co-Authors

Pressure-induced superconductivity in Iron pnictide compound SrFe2As2 (2008)

Igawa, K., Okada, H., Takahashi, H., Matsuishi, S., Kamihara, Y., Hirano, M., ...

Electrical resistivity under high pressure have been measured on nominally pure SrFe2As2 up to 14 GPa. The resistivity drop appeared with increasing pressure, and we clearly observed zero...

Superconductivity under high pressure in LaFeAsO (2008)

Okada, H., Igawa, K., Takahashi, H., Kamihara, Y., Hirano, M., Hosono, H., ...

Electrical resistivity measurements under high pressures up to 29 GPa were performed for oxypnictide compound LaFeAsO. We found a pressure-induced superconductivity in LaFeAsO. The maximum value of...

Magneto-transport properties governed by the antiferromagnetic fluctuations in heavy fermion superconductor CeIrIn$_{5}$ (2008)

Nakajima, Y., Shishido, H., Nakai, H., Shibauchi, T., Hedo, M., Uwatoko, Y., ...

In quasi-two dimensional Ce(Ir,Rh)In$_5$ system, it has been suggested that the phase diagram contains two distinct domes with different heavy fermion superconducting states. We here report the...

Positive and negative pressure effects on the magnetic ordering and the Kondo effect in the compound Ce2RhSi3 (2007)

Nakano, T., Sengupta, Kausik, Rayaprol, Sudhindra, Hedo, M., Uwatoko, Y., Sampathkumaran, E. V.

The competition between magnetic ordering and the Kondo effect in Ce2RhSi3, ordering antiferromagnetically at 7 K, is investigated by the measurements of magnetization, heat capacity and electrical...

Softening of Magnetic Excitations Leading to Pressure-Induced Quantum Phase Transition in Gapped Spin System KCuCl$_3$ (2007)

Goto, K., Osakabe, T., Kakurai, K., Uwatoko, Y., Oosawa, A., Kawakami, J., ...

KCuCl$_3$ is a three dimensionally coupled spin dimer system, which undergoes a pressure-induced quantum phase transition from a gapped ground state to an antiferromagnetic state at a critical...

Non-Fermi liquid behavior in the magnetotransport of CeMIn5 (M: Co and Rh): Striking similarity between quasi 2D heavy fermion and high-Tc cuprates (2006)

Nakajima, Y., Shishido, H., Nakai, H., Shibauch, T., Behnia, K., Izawa, K., ...

We present a systematic study of the dc-resistivity, Hall effect, and magnetoresistance in the normal state of quasi 2D heavy fermion superconductors CeMIn5 (M: Rh and Co) under pressure. Here the...

Evolution of Hall coefficient in two-dimensional heavy fermion CeCoIn$_5$ (2006)

Nakajima, Y., Izawa, K., Matsuda, Y., Behnia, K., Kontani, H., Hedo, M., ...

We report on the pressure dependence of the Hall coefficient $R_H$ in quasi-2D heavy fermion CeCoIn$_5$. At ambient pressure, below a temperature associated with the emergence of non-Fermi liquid...

Stoner gap in the superconducting ferromagnet UGe2 (2005)

Aso, N., Motoyama, G., Uwatoko, Y., Ban, S., Nakamura, S., Nishioka, T., ...

We report the temperature ($T$) dependence of ferromagnetic Bragg peak intensities and dc magnetization of the superconducting ferromagnet UGe2 under pressure ($P$). We have found that the low-$T$...

Electrical resistivity and tunneling anomalies in CeCuAs2 (2004)

Sampathkumaran, E. V., Ekino, T., Ribeiro, R. A., Sengupta, Kausik, Nakano, T., Hedo, M., ...

The compound CeCuAs2 is found to exhibit negative temperature (T) coefficient of electrical resistivity (rho) under ambient pressure conditions in the entire T-range of investigation (45 mK to 300...

Heat-capacity anomalies in the presence of high magnetic fields in the spin-chain compound, Ca3Co2O6 (2004)

Sampathkumaran, E. V., Hiroi, Z., Rayaprol, S., Uwatoko, Y.

Heat-capacity behavior in the presence of externally applied magnetic field (H) up to 140 kOe is investigated (2-35 K) for the quasi-1-dimensional compound, Ca3Co2O6, believed to order magnetically...

High pressure effects on the electrical resistivity behavior of the Kondo lattice, YbPd2Si2 (2004)

Nakano, T., Hedo, M., Uwatoko, Y., Sampathkumaran, E. V.

We report the influence of external pressure (P= up to 8 GPa) on the temperature dependence of electrical resistivity of a Yb-based Kondo lattice, YbPd2Si2, which does not undergo magnetic ordering...

Magnetic, electrical resistivity, heat-capacity and thermopower anomalies in CeCuAs2 (2004)

Sengupta, Kausik, Sampathkumaran, E. V., Nakano, T., Hedo, M., Abliz, M., Fujiwara, N., ...

The results of magnetic susceptibility, electrical resistivity ($\rho$), heat-capacity (C) and thermopower (S) measurements on CeCuAs2, forming in ZrCuSi2-type tetragonal structure, are reported. Our...

Magnetic behavior of Co ions in the exotic spin-chain compound,Ca3Co2O6, from 59Co NMR studies (2004)

Sampathkumaran, E. V., Fujiwara, N., Rayaprol, S., Madhu, P. K., Uwatoko, Y.

We have performed field-swept 59Co NMR measurements on the 'exotic' spin-chain material, Ca3Co2O6, crystallizing in K4CdCl6-type rhombohedral structure, believed to exhibit two magnetic transition...

Effect of Pressure on the Thermal Expansion Coefficient of the Heavy Fermion Material CeCu2Si2. (1998)

Takakura, H., Iki, K., Okita, H., Uwatoko, Y., Oomi, G.

Coefficient of thermal expansion alpha(T) of CeCu2Si2 was measured at 3-300K under high pressures up to 15 kbar; at low temperatures, the value of alpha/T showed a large enhancement, and alpha/T at 0...

Effect of Pressure on the Thermal Expansion Coefficient of Heavy Fermion Compounds MRu2Si2 (M=Ce,U). (1998)

Iki, K., Suenaga, K., Uwatoko, Y., Oomi, G., Sekine, C.

Thermal expansion of URu2Si2 and CeRu2Si2 has been measured under high pressure 20kbar; the contribution of crystal electric field splitting to thermal expansion of both compounds tends to disappear...

ANTIFERROMAGNETIC TO FERROMAGNETIC TRANSITION IN CsCl-TYPE CeZn1-xCdx COMPOUNDS (1988)

Uwatoko, Y., Fujii, H.

(00π)-type antiferromagnetism appears in the CeZn1-xCdx with x ≤ 0.50, whereas ferromagnetism is stabilized for x ≥ 0.60. At the intermediate content with x = 0.55, a spin-glass is...

ELECTRICAL PROPERTY OF SmAg1-xInx (1988)

Yagasaki, K., Yoshida, H., Kaneko, T., Uwatoko, Y., Kamigaki, K.

The electrical and Hall resistivities have been measured for SmAg1-xInx. The magnetic resistivity takes a minimum at x = 0.15 which may be due to changing sign of the s-f exchange integral. The...

LOW-TEMPERATURE SPECIFIC HEAT OF AN ANTIFERROMAGNETIC DENSE-KONDO COMPOUND CePdIn (1988)

Satoh, K., Maeno, Y., Fujita, T., Uwatoko, Y., Fujii, H.

Specific heat of a dense-Kondo compound CePdIn was measured down to 60 mK. Two anomalies in C/T were found at 1.7 and 0.9 K, and are discussed in terms of antiferromagnetic transition and formation...

MAGNETIC AND NEUTRON DIFFRACTION STUDIES OF CeZn2 SINGLE CRYSTAL (1988)

Fujii, H., Akayama, M., Uwatoko, Y., Hashimoto, Y., Kitai, T.

Metamagnetism with three-step processes due to spin-flop is observed at 4.2 K along the b-axis in the orthorhombic CeZn2. In the paramagnetic phase, strong anisotropy in the susceptibilities along...

ANTIFERROMAGNETIC TO FERROMAGNETIC TRANSITION IN CsCl-TYPE CeZn1-xCdx COMPOUNDS (1988)

Uwatoko, Y., Fujii, H.

(00π)-type antiferromagnetism appears in the CeZn1-xCdx with x ≤ 0.50, whereas ferromagnetism is stabilized for x ≥ 0.60. At the intermediate content with x = 0.55, a spin-glass is...

ELECTRICAL PROPERTY OF SmAg1-xInx (1988)

Yagasaki, K., Yoshida, H., Kaneko, T., Uwatoko, Y., Kamigaki, K.

The electrical and Hall resistivities have been measured for SmAg1-xInx. The magnetic resistivity takes a minimum at x = 0.15 which may be due to changing sign of the s-f exchange integral. The...

LOW-TEMPERATURE SPECIFIC HEAT OF AN ANTIFERROMAGNETIC DENSE-KONDO COMPOUND CePdIn (1988)

Satoh, K., Maeno, Y., Fujita, T., Uwatoko, Y., Fujii, H.

Specific heat of a dense-Kondo compound CePdIn was measured down to 60 mK. Two anomalies in C/T were found at 1.7 and 0.9 K, and are discussed in terms of antiferromagnetic transition and formation...

MAGNETIC AND NEUTRON DIFFRACTION STUDIES OF CeZn2 SINGLE CRYSTAL (1988)

Fujii, H., Akayama, M., Uwatoko, Y., Hashimoto, Y., Kitai, T.

Metamagnetism with three-step processes due to spin-flop is observed at 4.2 K along the b-axis in the orthorhombic CeZn2. In the paramagnetic phase, strong anisotropy in the susceptibilities along...

ANTIFERROMAGNETIC TO FERROMAGNETIC TRANSITION IN CsCl-TYPE CeZn1-xCdx COMPOUNDS (1988)

Uwatoko, Y., Fujii, H.

(00π)-type antiferromagnetism appears in the CeZn1-xCdx with x ≤ 0.50, whereas ferromagnetism is stabilized for x ≥ 0.60. At the intermediate content with x = 0.55, a spin-glass is...

ELECTRICAL PROPERTY OF SmAg1-xInx (1988)

Yagasaki, K., Yoshida, H., Kaneko, T., Uwatoko, Y., Kamigaki, K.

The electrical and Hall resistivities have been measured for SmAg1-xInx. The magnetic resistivity takes a minimum at x = 0.15 which may be due to changing sign of the s-f exchange integral. The...

LOW-TEMPERATURE SPECIFIC HEAT OF AN ANTIFERROMAGNETIC DENSE-KONDO COMPOUND CePdIn (1988)

Satoh, K., Maeno, Y., Fujita, T., Uwatoko, Y., Fujii, H.

Specific heat of a dense-Kondo compound CePdIn was measured down to 60 mK. Two anomalies in C/T were found at 1.7 and 0.9 K, and are discussed in terms of antiferromagnetic transition and formation...

MAGNETIC AND NEUTRON DIFFRACTION STUDIES OF CeZn2 SINGLE CRYSTAL (1988)

Fujii, H., Akayama, M., Uwatoko, Y., Hashimoto, Y., Kitai, T.

Metamagnetism with three-step processes due to spin-flop is observed at 4.2 K along the b-axis in the orthorhombic CeZn2. In the paramagnetic phase, strong anisotropy in the susceptibilities along...