Microstructure of Yb2Ba4Cu7Ox/Ag composites produced by oxidizing metallic procursors

✍ Scribed by T. Kogure; A. Otto; J.B. Vander Sande

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 499 KB
• Volume: 157
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(89)90027-0

✦ Synopsis

The mlcrostructure of a Yb2Ba4Cu7Ox/Ag m~crocomposlte formed by oxidation of metalhc precursors has been stud~ed mainly by transmission electron microscopy observations of ton thinned specimens. Yb2BaaCu70 x (2-4-7) grains have a distractive platehke shape, with the faces of the plates exhibiting a [001 ] normal thereby producing a large number of gram boundaries with [001 ] normals. On these grain boundaries YbBa2Cu4Ox (1-2-4) phase is often formed, otherwise the termination of 2-4-7 grams is always at the posit~on of the copper oxide single layer between barium Ions in th~s structure Some polytype structures w~th the 2-4-7 composmon have been identified and are described.