Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

91st Annual Meeting of the American Ceramic Society

Conference ·
OSTI ID:5406311

Phase relations at 850 and 870 C, melting transitions in air, oxygen, and helium were studied for Bi(2.1)Sr(1.9) CuO{sub 6} and for the Bi{sub 2}Sr{sub 2}Ca(n{minus}1) Cu(n)O(2n+4) for n = 1, 2, 3, 4, 5, and infinity (CaCuO{sub 2}). Up to 870 C, the n = 2 composition resides in the compatibility tetrahedron bounded by Bi(2+x)(Sr,Ca)(3{minus}y) Cu{sub 2}O{sub 8}, (Sr,Ca)14 Cu{sub 24}O{sub 41}, Ca{sub 2}CuO{sub 3}, and a Bi-Sr-Ca-O phase. The n is greater than or equal to 3 compositions reside in the compatibility tetrahedron Bi(2+x)(Sr,Ca)(3{minus}y) Cu{sub 2}O{sub 8} {minus} (Sr,Ca)14 Cu{sub 24}O{sub 41} {minus} Ca{sub 2}CuO{sub 3} {minus} CuO up to 850 C. However, Bi(2+x)Sr(4{minus}y) Cu{sub 3}O{sub 10} forms for n is greater than or equal to 3 after extended heating at 870 C. Bi(2+x)Sr(2{minus}y) CuO{sub 6} and Bi(2+x)(Sr,Ca)(3{minus}y) Cu{sub 2}O{sub 8} melt in air at 914 C and 895 C respectively. During melting, all of the compositions studied lose 1 to 2 percent by weight of oxygen from the reduction of copper. Bi(2+x)Sr(2{minus}y) CuO{sub 6}, Bi(2+n)(Sr,Ca)(3{minus}y) Cu{sub 2}O{sub 8}, and Bi(2+x)(Sr,Ca)(4{minus}y) Cu{sub 3}O{sub 10} exhibit crystallographic alignment in a magnetic field, with the c-axes orienting parallel to the field.

Research Organization:
National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
OSTI ID:
5406311
Report Number(s):
N-91-21910; NASA-TM--103749; E--6000; NAS--1.15:103749; CONF-890421--
Country of Publication:
United States
Language:
English