167 research outputs found
Stable Existence of Phase IV inside Phase II under Pressure in CeLaB
We investigate the pressure effect of the electrical resistivity and
magnetization of CeLaB. The situation in which phase IV
stably exists inside phase II at H=0 T could be realized by applying a pressure
above GPa. This originates from the fact that the stability of
phase II under pressure is larger than those of phases IV and III. The results
seem to be difficult to reproduce by taking the four interactions of
-type AFO, -type AFQ, -type AFO, and AF
exchange into account within a mean-field calculation framework.Comment: 4 pages, 5 figures, to appear in J. Phys. Soc. Jpn. 79 (2010) No.
Magnetic-Field-Induced 4f-Octupole in CeB6 Probed by Resonant X-ray Diffraction
CeB6, a typical Gamma_8-quartet system, exhibits a mysterious
antiferroquadrupolar ordered phase in magnetic fields, which is considered as
originating from the T_{xyz}-type magnetic octupole moment induced by the
field. By resonant x-ray diffraction in magnetic fields, we have verified that
the T_{xyz}-type octupole is indeed induced in the 4f-orbital of Ce with a
propagation vector (1/2, 1/2, 1/2), thereby supporting the theory. We observed
an asymmetric field dependence of the intensity for an electric quadrupole (E2)
resonance when the field was reversed, and extracted a field dependence of the
octupole by utilizing the interference with an electric dipole (E1) resonance.
The result is in good agreement with that of the NMR-line splitting, which
reflects the transferred hyperfine field at the Boron nucleus from the
anisotropic spin distribution of Ce with an O_{xy}-type quadrupole. The
field-reversal method used in the present study opens up the possibility of
being widely applied to other multipole ordering systems such as NpO2,
Ce_{x}La_{1-x}B_{6}, SmRu_{4}P_{12}, and so on.Comment: 5 pages, 4 figures, submitte
Laser ranging application to time transfer using geodetic satellite and to other Japanese space programs
Communications Research Laboratory (CRL) has been developing a laser time transfer system using a satellite laser ranging (SLR) system. We propose Japanese geodetic satellite 'AJISAI', launched in 1986 as a target satellite. The surface is covered not only with corner cube reflectors but also with mirrors. The mirrors are originally designed for observation of flushing solar light reflected by the separate mirrors while the satellite is spinning. In the experiment, synchronized laser pulses are transferred via specified mirror from one station to another while the satellite is up on the horizon to both stations. The system is based on the epoch timing ranging system with 40 ps ranging precision, connected together with UTC(CRL). Simulation study indicates that two stations at thousands of km distance from each other can be linked with signal strength of more than 10 photons and the distributed images of laser beam from AJISAI mirrors give many chances for two stations to link each other during a single AJISAI pass. Retro-reflector In Space for Advanced Earth Observation Satellite (ADEOS) and RendDezVous docking mission of Experimental Technology Satellite-7 (ETS-7) are briefly presented
Catalytic performance and QXAFS analysis of Ni catalysts modified with Pd for oxidative steam reforming of methane
Pd–Ni bimetallic catalysts prepared by co-impregnation and sequential impregnation methods were compared in the catalytic performance in oxidative steam reforming of methane. The sequential impregnation was more effective to the suppression of hot spot formation. According to the structural analysis by in situ quick-scanning X-ray absorption fine structure (QXAFS) during the temperature programmed reduction, the sequential impregnation method gave the bimetallic particles with higher Pd surface composition because of the low possibility of the Pd–Ni bond formation. Higher surface composition of Pd with higher reducibility than Ni is connected to the enhancement of the catalyst reducibility and the suppression of the hot spot formation
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