Title :
Preparation of La1.29Ca0.43Ba1.29Cu3Oy powder with different organic acids containing OH or NH2
Author :
Kao, H.-C.I. ; Shy, J.T. ; You, S.Y. ; Wang, C.M.
Author_Institution :
Dept. of Chem., Tamkang Univ., Tamsui, Taiwan
fDate :
3/1/2001 12:00:00 AM
Abstract :
More than ten organic acids containing hydroxyl or amino groups were selected as a medium to prepare submicrometer superconducting powder of La1.29Ca0.43Ba1.29Cu3 Oy by using a polymeric precursor method. Heat treated samples were analyzed by IR spectrometer for the degree of polymerization, by ICP and EDS for the homogeneity, by SEM for the particle size determination. Tc measurement and the purity examination were obtained by resistivity and X-ray diffraction, respectively. Organic acids containing three carboxyl groups are highly recommended for preparing high-Tc superconductors. It donates electron pairs for chelating with metal ions and also for the polyesterification with ethylene glycol. On the other hand, organic acids containing amino group along with two or less carboxyl acid groups are not recommended for this purpose
Keywords :
X-ray diffraction; barium compounds; calcium compounds; electrical resistivity; heat treatment; high-temperature superconductors; infrared spectra; lanthanum compounds; materials preparation; particle size; polymerisation; powder technology; scanning electron microscopy; superconducting transition temperature; EDS; ICP; IR spectra; La1.29Ca0.43Ba1.29Cu3 O; La1.29Ca0.43Ba1.29Cu3 Oy; SEM; Tc measurement; X-ray diffraction; XRD; amino groups; carboxyl groups; electron pairs; ethylene glycol; heat treated samples; high-Tc superconductors; homogeneity; hydroxyl groups; metal ions chelation; organic acids; particle size determination; polyesterification; polymeric precursor method; polymerization; preparation; purity examination; resistivity; submicrometer superconducting powder; Anti-freeze; Conductivity; High temperature superconductors; Infrared spectra; Polymers; Powders; Solid state circuits; Spectroscopy; Superconducting materials; X-ray diffraction;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
