巻号一覧
67 巻, 1 号
選択された号の論文の68件中51～68を表示しています
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Tetsuo Okane, Mitsuki Yamada, Shoji Suzuki, Shigeru Sato, Akito Kakiza ...専門分野: Electronic structure and electrical properties of surfaces, interfaces and thin films.
1998 年 67 巻 1 号 p. 264-271
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありWe have studied the electronic structures of Ce/Ni(110) and Ce/Cu(110) systems by measuring Ce 3d core-level X-ray photoelemission and Ce 4d-4f resonant photoemission. The distribution of the Ce atoms in the surface layers was investigated by means of a medium-energy ion scattering experiment. It was found that in Ce/Ni(110) Ce atoms occupy substitutional sites of the Ni substrate lattice after annealing. In the Ce/Ni(110) system, the Ce 4f electronic structure depends on the content of Ce atoms in the surface layers and shows considerable change by annealing. In the Ce/Cu(110) system, the Ce 4f electronic structure is insensitive to the Ce concentration in the surface layers. The difference of Ce 4f electronic structures between two systems is discussed in connection with the difference of the hybridization strength of Ce 4f and electronic states of the substrates.抄録全体を表示PDF形式でダウンロード (701K) -
Masato Hedo, Yoshihiko Inada, Etsuji Yamamoto, Yoshinori Haga, Yoshich ...専門分野: Superconductivity.
1998 年 67 巻 1 号 p. 272-279
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありWe have measured the specific heat and the magnetization in the superconducting mixed state of CeRu2 at low temperatures and in high magnetic fields. We have clarified a rich variety of superconducting properties such as the temperature dependence of the electronic specific heat and Maki parameters κ1, κ2 and κ3.From these experimental results, CeRu2 is concluded to be of the BCS-type in superconductivity.Nevertheless, interesting is the magnetic field dependence of the electronic specific heat at 0.5K, indicating a √H like behavior in low fields and a H-linear dependence in high fields up to the upper critical field of 50kOe.This characteristic specific heat is discussed on the basis of a microscopic theory by Brandt et al.抄録全体を表示PDF形式でダウンロード (612K) -
Shigemasa Matsuo, Seiji Higashitani, Yasushi Nagato, Katsuhiko Nagai専門分野: Superconductivity.
1998 年 67 巻 1 号 p. 280-289
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe phase diagram of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state in a 3-dimensional superconductor is discussed. We usethe quasi-classical Green's function to calculate the free energy.It is shown that the phase transition from the normal state is of first order at high temperatures but is of second order near T=0.To describe the phase transition in the Ginzburg-Landau theory, onehas to take into account up to eighth order term with respect to the order parameter. The phase transition from the FFLO state to the uniform superconducting state is of second order in all the temperature range T<0.561Tc in accordance with Burkhardt and Rainer's result in a 2-dimensional system.抄録全体を表示PDF形式でダウンロード (758K) -
Kichizo Asai, Atsuro Yoneda, Osamu Yokokura, J. M. Tranquada, G. Shira ...専門分野: Magnetic properties and materials.
1998 年 67 巻 1 号 p. 290-296
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありNeutron-diffraction measurements have revealeda new anomalous thermal lattice expansion of LaCoO3 near 500 K thatindicates the existence of a second spin-state transition, in addition to theone previously established near 100 K. The anomalous expansion and thetemperature dependence of the Co magnetic moments are successfullyinterpreted in a wide temperature range based on a simple model assuminglow-spin (LS, S=0), intermediate-spin (IS, S=1), and high-spin(HS, S=2) states of Co atoms.The first spin transition, near 100 K, is from LS to IS, andthe second, near 500 K, is from IS to a mixed state of IS and HS.The fitted model parameters indicate that the initially-large energy differencebetween IS and HS states decreases towards zero as the secondtransition proceeds. The large drop in resistivity associated with the lattertransition appears to be correlated with the population of the HS state.抄録全体を表示PDF形式でダウンロード (664K) -
Aya Tobo, Atsuko Ito専門分野: Magnetic properties and materials.
1998 年 67 巻 1 号 p. 297-301
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe temperature variations of linear and nonlinear ac-susceptibilities have been measured for both spin-glass and reentrant-spin-glass samples of the diluted antiferromagnet MnxMg1-xTiO3. In the temperature variations of the nonlinear susceptibility, a divergence-like peak is observed for the spin-glass samples with x=0.54 and x=0.56 at the respective spin-glass freezing temperatures. A distinct anomaly is also observed for the reentrant-spin-glass sample with x=0.60 at the reentrant transition temperature, indicating a divergent nature of the nonlinear susceptibility. As far as the authors know, it is the first observation for antiferromagnet-base reentrant-spin-glasses. Although the detail of the reentrant transition has not been understood very well yet, this anomaly may suggest experimentally that the reentrant transition should be a genuine cooperative phenomenon of the spin system.抄録全体を表示PDF形式でダウンロード (393K) -
Masayoshi Tsukano, Kiyohide Nomura専門分野: Magnetic properties and materials.
1998 年 67 巻 1 号 p. 302-306
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPhase diagram of S=1 XXZ chain in a staggered magnetic field is obtained numerically. TheBerezinskii-Kosterlitz-Thouless transition between the XY and the antiferromagnetic phases isstudied by the level-spectroscopy. Moreover we find that there is no distinction between theHaldane and the antiferromagnetic phases, since the Gaussian critical line does not appear, incontrast to the S=1/2 case. It is expected that some hidden Z2× Z2 symmetry breakinghappens not only in the Haldane phase but also in the antiferromagnetic one.抄録全体を表示PDF形式でダウンロード (362K) -
Takashi Kiyama, Kazuyoshi Yoshimura, Koji Kosuge, Herwig Michor, Gerfr ...専門分野: Magnetic properties and materials.
1998 年 67 巻 1 号 p. 307-311
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe specific heat of (Sr--Ca)RuO3 system was measured by an adiabatic method utilizing a heat-pulse technique. The values of electronic specific heat coefficient γ change from 30, mJ/molK2 for SrRuO3 to 82, mJ/molK2 for CaRuO3 through a maximum value of about 100, mJ/molK2 for Sr0.2Ca0.8RuO3. A strong upturn in the C/T vs T2 curve at low temperatures has been observed for paramagnetic Sr0.2Ca0.8RuO3 and CaRuO3. This behavior is quantitatively explained by the spin-fluctuation theory of the itinerant-electron magnetism, suggesting that this system possibly changes from intermediate itinerant ferromagnet of SrRuO3, through weakly itinerant ferromagnet, to nearly ferromagnetic metal of CaRuO3.抄録全体を表示PDF形式でダウンロード (430K) -
Yutaka Itoh, Takato Machi, Seiji Adachi, Atsushi Fukuoka, Keiichi Tana ...専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1998 年 67 巻 1 号 p. 312-317
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありWe report the doping dependence of the planar 63Cu Knight shift (63K), the nuclear spin-lattice relaxation rate 63(1/T1T) and the Gaussian spin-echo decay rate 63(1/TG) for the high-Tc monolayer HgBa2CuO4+δ over a wide doping range [Tc=50, 72, 82, K (underdoping), 96, K (optimal doping) and 30, K (overdoping)], measured by the Cu NMR spin-echo technique. We found the following new facts; (1) both the static and the dynamical spin susceptibilities exhibit the pseudo spin-gap behavior over a wide q region around the staggered mode Q, (2) the dynamical pseudo spin-gap in 1/T1T can mainly be ascribed to the static one in 1/TG, and (3) a spin fluctuation amplitude probed by the empirical ratio T1T/(TG)2 is a monotonic decreasing function of the doping level but not proportional to Tc. From comparison with La2-xSrxCuO4, we discussed the role of the pseudo spin-gap in the high-Tc superconductivity.抄録全体を表示PDF形式でダウンロード (546K) -
Izumi Tomeno, Masayuki Oguchi専門分野: Magnetics resonances and relaxations in condensed matter; MÖssbauer effect.
1998 年 67 巻 1 号 p. 318-322
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe 7Li and 6Li nuclear spin-lattice relaxation rates, (7T1)-1 and (6T1)-1, have been measured for LiCoO2 as a function of temperature. Comparison between 7Li- and 6Li-rich samples shows that the ratio (6T1)-1/(7T1)-1=0.06 is considerably larger than the value expected for quadrupolar relaxation processes. Furthermore (7T1)-1 decreases significantly as 7Li is replaced by 6Li. These observations indicate that (7T1)-1 is dominated by the nuclear magnetic dipole-dipole interaction between the 7Li nuclei. The substitution of Cr for Co has no effect on (7T1)-1 in the range below 200, K, whereas the substitution of Na for Li enhances (7T1)-1. The substitution effect supports the view that the two-dimensional Li ion motion is dominant in LiCoO2. The weak dependence of (7T1)-1 upon temperature and frequency suggests the presence of a broad distribution of barrier heights for ionic motion in LiCoO2.抄録全体を表示PDF形式でダウンロード (423K) -
Makoto Nakazawa, Haruhiko Ogasawara, Akio Kotani, Pierre Lagarde専門分野: Optical properties and condensedmatter spectroscopy and other interactions of matter with particles and radiation.
1998 年 67 巻 1 号 p. 323-331
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありWe analyze fluorescence yield spectraof rare earth oxides at 3d threshold regionby means of ionic model with full multiplet effects.The calculation is based on the second-order optical formula, and the effect of the polarization of incident and emitted X-raysis taken into account.The calculated results are in satisfactory agreement with recentexperimental data.The difference between fluorescence yield spectra and 3d X-ray absorptionspectra is explained.抄録全体を表示PDF形式でダウンロード (563K) -
Takako Iizuka–Sakano, Eiichi Hanamura専門分野: Optical properties and condensedmatter spectroscopy and other interactions of matter with particles and radiation.
1998 年 67 巻 1 号 p. 332-339
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe spectrum of resonant second-harmonic generation (SHG) isfar sharper than that of linear photo-absorption (LA), as observed for Cr2O3 crystal. We show theoretically this comes from the difference that strong coupling between the localized electronic excitation and latticevibration works as intermediate state interaction in SHG while it does as final state interaction in LA.抄録全体を表示PDF形式でダウンロード (623K) -
Eiichi Yagi, Shigetoshi Koike専門分野: Materials science.
1998 年 67 巻 1 号 p. 340-344
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありThe site occupancy of hydrogen in Nb--20 at.%Mo alloys is investigated at room temperature for H concentrations (CH) 2.6, 4.2, and 8.0 at.% by a channelling method using a nuclear reaction 1H(11B}, α )α α . Different from previous results for lower Mo concentrations, a large portion of H atoms are at tetrahedral (T) sites and, in addition, the octahedral (O) site occupancy is newly observed. The hydrogen distribution changes with CH. At CH=2.6 and 4.2 at.%, the 20--30% of H atoms are located at O sites, while at CH=8.0 at.% the fraction of the O-site occupancy remarkably decreases to 0--10%.抄録全体を表示PDF形式でダウンロード (438K) -
Go Uchida, Yuuki Mizukami, Tomomi Nemoto, Yoshimi Tsuchiya専門分野: Biophysics.
1998 年 67 巻 1 号 p. 345-350
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありWe have investigated the sliding movement of magnetizable beads coated with Chara motor protein in a magnetic field using a Characean motility assay system.In the present study only the motion of the beads moving in the opposite direction to the magnetic force exerted on them has been observed. This investigation has revealed that Hill's type equation describes relation between average sliding velocity of the beads and the magnetic force.We have also obtained traces of the single beads at every 1/30 s in order to investigate the sliding motion of the beads from a stochastic viewpoint.Application of our stochastic model for the sliding movement to analysis of the traces has made it clear that while the stroke frequency remains constant with increase of the magnetic force, the distance of the beads moved by a single impulse due to the interaction between the motor protein and actin decreases.抄録全体を表示PDF形式でダウンロード (421K) -
Mufei Xiao, Xin Chen専門分野: Molecular spectra and interactions of molecules with photons.
1998 年 67 巻 1 号 p. 351-352
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (152K) -
Shin–ichi Kondo, Nobukazu Yamagishi, Tadaaki Saito専門分野: Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties).
1998 年 67 巻 1 号 p. 353-354
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (179K) -
Takayuki Nakada, Takehiko Ishiguro, Takeshi Miura, Yohji Misaki, Tokio ...専門分野: Electronic transport in condensed matter.
1998 年 67 巻 1 号 p. 355-356
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (165K) -
Hiroshi Kageyama, Kazuyoshi Yoshimura, Koji Kosuge, Xun Xu, Shinji Kaw ...専門分野: Magnetic properties and materials.
1998 年 67 巻 1 号 p. 357-358
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (126K) -
Hiroyuki Mashiyama, Jiyou Wu, Fuminao Shimizu, Masaaki Takashige専門分野: Dielectric properties and materials.
1998 年 67 巻 1 号 p. 359-360
発行日: 1998/01/01
公開日: 1999/10/01
ジャーナル 認証ありPDF形式でダウンロード (192K)