Analysis of wide-angle laser scattering intensity distribution for discriminating single microscopic particles

The laser light scattering pattern in a wide angle is measured using a system designed and constructed to employ a linear 512-photodiode array for the morphological investigation of single microscopic particles and biological cells. The experimental intensity distribution exhibits a fairly good correlation with the size and structure of the microscopic object. The method is applicable to the real-time morphological analysis of individual biological cells in a flow system.     

Asymmetric synthesis of β-lactams. I. The reaction of dimethylketene silyl acetal with (S)-alkylidene(1-arylethyl)amines promoted by titanium tetrachloride

Asymmetric synthesis of β-lactams by means of the reaction of dimethylketene silyl acetal with (S)-alkylidene(1-arylethyl)amines in the presence of titanium tetrachloride was studied. The extent of the asymmetric induction was in the range of 44–78% (diastereomeric purity 72–89%) and the (S)-configuration was turned to be preferentially induced at the ⁴C position of the resulting β-lactams.     

FePt L10 ordering and grain growth using millisecond pulse laser processing

The structural and magnetic properties of ∼12 nm thick FePt thin films grown on Si substrates annealed using a 1064 nm wavelength laser with a 10 ms pulse have been examined. The A1 to L1₀ ordering phase transformation was confirmed by electron and X-ray diffraction. An order parameter near 50% and a maximum coercivity of 12 kOe were obtained with laser energy densities of 25-32 J/cm². Grain growth, quantified by dark field transmission electron microscopy, occurred during chemical ordering at the laser pulse widths studied.     

Formation of bcc-Ni thin film on GaAs(100) substrate and phase transformation from bcc to fcc

Ni thin films are prepared on GaAs(100) single-crystal substrates at room temperature by using an ultra-high vacuum radio-frequency magnetron sputtering system. The growth behavior and the crystallographic properties are studied by in-situ refection highenergy electron diffraction and pole-figure X-ray diffraction. In an early stage of film growth, a metastable bcc Ni(100) single-crystal film is formed on GaAs(100) substrate, where the bcc structure is stabilized through hetero-epitaxial growth. With increasing the film thickness, fcc crystals coexist with the bcc(100) crystal. High-resolution cross-sectional transmission electron microscopy shows that the film consists of a mixture of bcc and fcc crystals and that a large number of planar faults exist parallel to the fcc(111) close-packed plane. The results indicate that the bcc structure starts to transform into fcc structure through atomic displacement parallel to the bcc{110} close-packed planes.     

Development of rotating magnetic field system for the β-NMR method

A rotating magnetic field system has been developed to determine the sign of magnetic (μ) and quadrupole (Q) moments by means of the β-ray-detected nuclear magnetic resonance (β-NMR) method. The rotating magnetic field is obtained using two crossed Helmholtz-like coils at right angles. The phase angles of the alternating currents for the two coils are shifted by 90°. Thus the resulting magnetic field is circularly polarized. By the adjustment of the phase-angle difference, a right- or left-circularly polarized magnetic field is produced. Productions of right- or left-rotating magnetic fields including a linear component were confirmed using pickup-coils.