Structure and Properties of Novel Cuprates

While Sr sub 2 YCu sub 3 O sub 7 is not a stable phase replacement of some Cu with Al, Pb, Co, or Fe leads to stable phases of formula Sr sub 2 YCu sub (3-x) M sub x O sub 7. For Al, Co, and Fe the solid solution ranges from 0.4=x=1.0 while for Pb only samples near x=0.5 are single phase. The Al samples indicate an oxygen content of seven while the other metals show an increased oxygen content at high dopant levels. The detailed structural and transport behavior of these materials will be discussed. The above mentioned phases demonstrate the subtle changes that can lead to phase stabilization. A thorough search for other copper based oxides has been conducted with this in mind. The results of this search will also be presented.