MINUTE DOPING OF PULSED LASER DEPOSITION PROCESSED Y123 THIN FILMS WITH TB, CE, AND PR

by Kell, Joseph William

Three rare earth elements (Tb, Ce, and Pr) were chosen for the investigation into whether adding minute quantities (?1 at%) of dopants could improve the film quality of YBa 2Cu 3O 7-?(Y123) thin films. The compositions studied are (Y 1-x,Re x)Ba 2Cu 3O 7-?(RE=Tb, Ce, Pr; x=0.1, 0.01, 0.001). Good quality thin films were produced by PLD and showed significant improvement to properties when exposed to a magnetic field. Ce and Pr (x=0.001) doped films showed modest improvement. However, the Tb doped system showed substantial improvement to J c(H), with a total improvement in the (Y 0.99,Tb 0.01)-123 system of over a full order of magnitude by 5T and peaking at ~22.5x at 6T at 77K and the total improvement at 65 K showing a full doubling of J cby 6T and a tripling by 9T. TEM analysis showed that a large amount of nanoparticles and planar defects are likely causes of the increase to J c(H) for (Y 0.99,Tb 0.01)-123 films.