Showing papers by "Tatsuo C. Kobayashi published in 2010"
TL;DR: In this article, a flexible microporous coordination polymer, CPL-2 [Cu 2 (pzdc) 2 (bpy)]·(pzhdc = pyrazine-2,3-dicarboxylate; bpy = 4,4'-bipyridine), possessing bellows-shaped one-dimensional channels was measured.
24 citations
01 Jan 2010
TL;DR: In this paper, high-field magnetization measurements have been performed at various temperatures on the molecular oxygen adsorbed in a microporous coordination polymer CPL-1, and the magnetic properties can be explained by not the S = 1 Heisenberg antiferromagnetic dimer model but the O2-O2 dimers model taking into account the spin-dependent intermolecular potential.
Abstract: High-field magnetization measurements have been performed at various temperatures on the molecular oxygen adsorbed in a microporous coordination polymer CPL-1. Molecular oxygen with S = 1 forms O2-O2 dimer in the nanochannels of CPL-1. The magnetic properties can be explained by not the S = 1 Heisenberg antiferromagnetic dimer model but the O2-O2 dimer model taking into account the spin-dependent intermolecular potential. This feature is attributed to the fact that the magnetic interaction between O2 is comparable to the van der Waals force.
3 citations
TL;DR: In this article, the authors measured nuclear quadrupole resonance (NQR) for 63 Cu nuclei under high pressure up to 4.8 GPa and found that bulk superconductivity suddenly disappears at 4.5 GPa.
Abstract: We have measured nuclear quadrupole resonance (NQR) for 63 Cu nuclei under high pressure up to 4.8 GPa. A linear increase in NQR frequency 63 v Q of 63 Cu nuclei was observed below 3 GPa. However, 63 v Q deviates gradually from the linear relation above 3.5 GPa. The downward deviation is associated with a change of valence and consistent with the results of band calculations with the structural parameters under pressure. Antiferromagnetic (AFM) spin fluctuations are drastically suppressed with increasing pressure, whereas T c increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level.
3 citations
TL;DR: In this article, the magnetic properties of O2 adsorbed in the microporous coordination polymer Cd(bpndc)(bpy) were investigated by means of high-field magnetization measurement.
Abstract: The magnetic properties of O2 adsorbed in the microporous coordination polymer Cd(bpndc)(bpy) were investigated by means of high-field magnetization measurement. The magnetization of adsorbed O2 has a paramagnetic-like behavior in the low-field region and increases steeply above 50 T. The experiment results suggest that the half of adsorbed O2 that forms O2–O2 dimer causes the metamagnetic-like behavior and the remaining O2 causes paramagnetic-like behavior owing to nearly isolated spin. A possible arrangement of O2 is suggested.
2 citations