J. Phys. Colloques
Volume 49, Numéro C6, Novembre 198835th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
|Page(s)||C6-447 - C6-452|
J. Phys. Colloques 49 (1988) C6-447-C6-452
AN APFIM/FEM INVESTIGATION OF PLANAR DEFECTS IN HIGH TEMPERATURE SUPERCONDUCTORSM.K. MILLER1, A.J. MELMED2 et K.L. MORE1
1 Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6376, U.S.A.
2 National Bureau of Standards, Gaithersburg, MD 20899, U.S.A.
A combined field-ion microscopy and field emission microscopy study of RBa2Cu3O7-x, where R is Y, Yb or Sm, high temperature superconducting oxides has been performed. High quality field-ion hydrogen and argon images have been obtained. The oxide was usually found to exhibit a characteristic striped pattern in both hydrogen and argon field-ion images. These stripes were usually uniform in intensity. The presence of planar defects have been observed as stripes that have a different intensity or as an individual stripe that abruptly changes intensity. A thin phase was also observed at grain boundaries. This boundary phase imaged darkly in both field-ion and field emission images taken below the critical superconducting transition temperature. The presence of these defects possibly degrades the electrical properties of the bulk material.