| Budget Amount *help |
¥3,570,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥270,000)
Fiscal Year 2007: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
UIr is the Ising-type ferromagnet without inversion symmetry and its Curie temperature is 46 K and the easy axis is along the [10-1] axis. With increasing the pressure, there are three ferromagnetic phases named FM1, FM2 and FM3 and Uir becomes paramagnetic when the pressure goes over the FM3 region. Near the quantum critical point at which the Curie temperature of the FM3 phase vanishes, 2.6-2.7GPa, the superconductivity is found by the electrical resistivity measurement.
In this study, we measured the Meissner effect in the FM3 phase by the AC magnetic susceptibility measurement. In the ferromagnetic FM2 phase, the electrical residual resistivity along the magnetic easy axis [10-1] does not so change in the FM1 and FM3 phases, but the electrical residual resistivity along [010] is larger about ten times than the one in the FM1. From the electric resistivity measurement near the critical pressure, the upper critical magnetic field at 0 K becomes about 15 and 32mT along [101] and [10-1], respectively. We succeeded to measure the de Haas-van Alphen (dHvA) effect along the [010] axis under pressure. There are 5 dHvA branches at 1.0GPa and 3 ones at 1.5GPa and the cyclotron effective masses of these branches are not so different from ones at ambient pressure
In addition, we produced a new compound URh. Our URh sample is an almost single crystal. From X-ray diffraction, the crystal structure of URh is monoclinic PbBi-type and a=5. 604A, b=10. 451A, c=5. 607 A, β=100. 07°. It is same as UIr. URh has the Ising-type magnetic anisotropy and the Saturation magnetization is 0.65μ_<B'>, which is larger than one of UIr.
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