Structural changes in lanthanide doped YBa2Cu4O8

Abstract The structural changes induced by substitution of several lanthanides (LnLu, Tb, Gd, Pr and Ce) for Y in the high- T c superconductor YBa 2 Cu 4 O 8 have been studied by neutron powder diffraction. A series of samples with varying contents of Lu and Gd was prepared. Codoping with Sr was observed to increase the solubility of Lu. A drastic depression of T c is observed for Ce doped Y-124 due to hole filling, that is not compensated by charge transfer from the double CuO chains.