Motoko Akita

Dynamic structural conversion in a spin-crossover cobalt(II) compound with long alkyl chains

A cobalt(ii) compound [Co(C14-terpy)(2)](BF(4))(2).MeOH (1) with long alkyl chains was prepared, and exhibited unique SCO at T(1) = 50 K and spin transition at T(2) upward arrow = 206 K and T(2) downward arrow = 184 K with hysteresis (DeltaT = 22 K) accompanying the motion of the long alkyl chains.

Magnetic Levitation of Plastic Chips: Applications for Magnetic Susceptibility Measurement and Magnetic Separation

Magnetic levitation of polyethylene, polycarbonate, polypropylene, polystyrene, poly(methyl methacrylate) and polyamide was carried out using a compact superconducting magnet (vertical bore, 1500 T2 m-1). First, their diamagnetic susceptibilities were calculated from the product of the magnetic field and the field gradient necessary for levitation. Second, polypropylene, polyamide, and poly(ethylene terephthalate) chips were separated by magnetic levitation. Magnetic levitation is shown to be a convenient and useful technique for both diamagnetic susceptibility measurements and magnetic separations of diamagnetic substances.

Crystallographic Chirality of CsCuCl3 Probed by Resonant Circularly-Polarized Hard X-ray Diffraction

We have observed the circular-polarization-dependent intensities of forbidden (0, 0, 6 n ±2) reflections at the Cu K absorption edge in the chiral crystal CsCuCl 3 . The intensities for the right- and left-handed circularly-polarized incident beams interchange in CsCuCl 3 crystals with opposite chiralities. The result is well explained by a model calculation based on the anisotropic tensor susceptibility of Cu 2+ ions, taking only the electric-dipole ( E 1) process into account. This technique can determine crystallographic chirality by measuring the flipping ratio for only one reflection, in principle.

Polymerization of N-isopropylacrylamide under magnetic levitation

A study of an effect of the magnetic levitation on polymerization of N-isopropylacrylamide at room temperature was carried out. The magnetic levitation environment, which is created by strong and upward magnetic force counterbalanced with the downward gravitational force, is multiple environment consisting of both the microgravity and the strong magnetic field which is lacking in a space vehicle orbiting around the earth. In this work, the effect was evaluated from the viewpoint of the number-average molecular weight (Mn) and the polydispersity (the index of the molecular weight distribution) of the synthesized polymer. A small extent (~10 %) of the effect was observed on both the parameters. When the polymer was synthesized under the magnetic levitation environment, Mnincreased while the polydispersity decreased as compared with those of the polymer synthesized under the gravity.

Magnetocrystalline Anisotropy and Crystal Fields in the Weak-Ferromagnet Ce4Ni3Pb4

We report measurements of magnetization, magnetic susceptibility, specific heat, and neutron diffraction on a single crystal of the heavy fermion compound, Ce 4 Ni 3 Pb 4 , crystallizing in a trigonal structure with two inequivalent Ce sites. In the paramagnetic state, the effect of crystal electric field (CEF) leads to the easy magnetization direction along the c -axis. Magnetic Bragg peaks develop below T N =3.0 K and are indexed with a propagation vector k =[0,1,1/2]. Below T N , a spontaneous moment of 10 -3 µ B /Ce is observed only for B ⊥ c , while a metamagnetic transition is observed for B ∥ c at 1.3 T. The small spontaneous moment in the c -plane is ascribed to the slight canting of the antiferromagnetically aligned moments from the c -axis. The inelastic neutron scattering spectrum is composed of four CEF excitations at 5.3, 19, 24, and 40 meV. The peaks at 19 and 40 meV have a rather large width of 10 meV, which is three times larger than that of the others. The wide peaks are assigned to excit...