Magnetic evaluation of intergranular interactions in thin-film media by rotational hysteresis loss analysis

Magnetic torque analysis has been carried out for CoNiPt, CoCrTa/Cr and CoCrPt/Cr thin-film media. The magnetic field H^grain_k, where the rotational hysteresis loss vanishes, remained almost constant in each material, independent of the coercive force H_c. Only in the CoCrTa media no clear correlation between the rotational hysteresis integral and H_c was observed.     

NMR study of μc-Si:H

The behavior of hydrogen in glow-discharge (GD) μc-Si:H has been characterized by ¹H NMR. The ¹H spectra consist of two components with different linewidths. The linewidth (FWHM) of the narrow component is about 0.5 kHz at ν₀ = 90 MHz, being much narrower than has been observed in GD a-Si:H deposited under a conventional low RF-power condition. It has been demonstrated that the 0.5-kHz FWHM component originates from the hydrogens in motional narrowing state, and such fast-moving hydrogens are incorporated both in μc-Si:H and high-power deposited a-Si:H.     

Superconducting property of Zr–Co and Zr–Co–Al alloys fabricated by rapid solidification

The superconducting property of Zr_(1−x)Co_x (x = 10–50 at.%) alloys and a Zr₅₅Co₃₀Al₁₅ bulk metallic glass fabricated using techniques of rapid solidification was investigated. The Zr₅₅Co₃₀Al₁₅ alloy crystallized by heat treatment in a vacuum atmosphere exhibited superconductivity of T_c,on = 2.4 K. This was attributable to the superconducting property of a crystalline Zr–Co alloy precipitated in the Zr₅₅Co₃₀Al₁₅ alloy. The T_c,on of the crystalline Zr_(1−x)Co_x alloy was sensitive to the Co content. The increase of Co content for the Zr_(1−x)Co_x alloy led to the decrease of T_c,on. The Zr_(1−x)Co_x alloy exhibited superconductivity of a maximum T_c,on = 3.9 K for the Zr₈₀Co₂₀ alloy with superconducting nanocrystal particles embedded in the amorphous matrix.     

Synthesis and radical polymerization of methacrylate endowed with bicyclobis(γ‐butyrolactone) moiety through methylene linker

A series of methacrylates bearing bicyclobis(γ‐butyrolactone) (BBL) moiety were synthesized and radically polymerized to afford the corresponding poly(methacrylate)s bearing BBL moiety in the side chain, with expecting that the high polarity and rigidity of BBL would be inherited by the polymers. The resulting polymers were soluble in polar aprotic solvents such as dimethyl sulfoxide and N,N‐dimethylformamide because of the high polarity of the BBL moiety. The glass transition temperatures (T_g) of the polymers depended on the length of methylene linker that tethered the methacrylate and BBL moieties, making the use of shorter linkers lead to higher T_gs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2462–2468     

Conformational analysis of N-aryl-N-(2-azulenyl)acetamides

Aromatic amides bearing 2-azulenyl group on the amide nitrogen were synthesized and their structures were investigated. The π-electron density of the N-aryl group was found to influence the cis-trans conformational preferences of these compounds in solution. X-ray crystallography revealed that the plane of the 2-azulenyl ring has a strong tendency to lie coplanar with the amide plane when the azulene group is located on the same side as the amide oxygen atom.