Makoto Nishino

X-Ray Diffraction Study on the Crystal Structure of Nd1+xBa2-xCu3O7-δ

Crystal structures in the Nd1+xBa2-xCu3O7-δ system have been investigated by X-ray powder diffraction combined with Rietveld analysis. The compound NdBa2Cu3O7-δ is isomorphic with orthorhombic YBa2Cu3O7-δ. With the increase of x the orthorhombic distortion decreases, and the compound becomes tetragonal at x=0.2. The tetragonal structure is isomorphic with the tetragonal form of YBa2Cu3O7-δ. Tc of the compounds with x=0 and 0.05 is above 90 K, which decreases monotonically with x and the compound becomes semiconducting at x=0.4.

Crystal Structure of the High Tc Superconductor LnBa2Cu3O7-δ (Ln=Sm, Eu and Gd)

The crystal structure of the high Tc superconductor LnBa2Cu3O7-δ (Ln=Sm, Eu and Gd) has been determined by Rietveld analysis of X-ray powder diffraction data. The compounds crystallize in an oxygen-deficient layered perovskite structure with space group Pmmm. The structure is isomorphic with YBa2Cu3O7-δ. The Ln and Ba atoms have an ordered arrangement, oxygen on a z=1/2 plane is missing and the oxygen site on the basal Cu plane is selectively occupied.

Data Processing for Obtaining Atomic Images from SrTiO3 X-Ray Fluorescence Hologram

It is difficult to obtain a clear atomic image from a measured X-ray fluorescence hologram, because the holographic undulation in the angular distribution of the X-ray fluorescence intensity is feeble. We introduce here our numerical data process to reconstruct an atomic image from the SrTiO3 (001) hologram data reported in a previous paper [J. Kawai et al..: Anal. Sci. 14 (1998) 903]. The holographic oscillation, which could not be seen in the raw data, was revealed by the Savitzky-Golay smoothing method. We also considered the effect of the hologram size on the reconstructed image of Sr atoms, and found that the spatial resolution of the image became higher with an increase of the size in the hologram.

Measurement of polymer film thickness based on throretical calculation of Rh K.ALPHA. X-ray Compton scattering intensity.

Rhターゲットを持つX線管から発生し,試料によって散乱されるRh Kαコンプトン散乱X線の強度を理論的に計算し,これと測定強度との比較により樹脂薄膜の膜厚を決定する方法について検討した.X線強度の計算は,測定されるRh Kαコンプトン散乱X線が,ターゲット物質の特性X線であるRh Kαのコンプトン散乱と連続X線のレイリー散乱及びそのコンプトン散乱から構成されているものとして行った.蛍光X線分析装置の元素感度係数を定めるための標準試料としてはバルク(塊)状のポリテトラフルオロエチレンを用いた.この方法によるポリエチレンやポリプロピレンなど樹脂薄膜の膜厚の定量値は,接触式万能測長機による測定値4～260μmに対して最大1μmの範囲で一致した.又,鉄など無機元素を含む単層あるいは2層の樹脂薄膜の層の膜厚や含有成分の面積密度も定量したところ,これらの薄膜の膜厚も万能測長機の測定値214～220μmに対してX線定量値は1～5μmの範囲に,更に,成分の面積密度は公称値1mg/cm2に対し0.01～0.03mg/cm2の範囲で一致した.