Cation doping in YBa 2Cu 4O 8

Abstract

Computer simulation techniques have been used to study the structural changes caused by Zn, Ce, Pr, Th, Ca, Sr, Fe, Co, and Ni doping in YBa 2Cu 4O 8. We found that benefical dopants (Ca and Sr) and deleterious dopants (Pr, Th, Zn, Ce, Fe, Co and Ni) caused very different structural changes in Cu(2)O(1), Cu(1)O(4′), z(Ba) Z(O(1)), Cu(2)O(2) and Cu(2)O(3). It appears that Ca-doped YBa 2Cu 4O 8 is under “positive chemical pressure” while YBa 2Cu 4O 8 doped with deleterious dopants behaves as if it is under “negative chemical pressure”.