Published online by Cambridge University Press: 26 February 2011
PrBa2Cu2NbO8 (PrBCNO) is an insulating analog to the YB2CU3O7 (YBCO) system, which is interesting as a thin film buffer layer in YBCO/PrBCNO/YBCO tunnel junctions as well as a potential high Tc superconductor if proper doping could be achieved. PrBCNO has a similar structure to PrBCO, with NbO2 planes replacing the CuO chains. Single phase polycrystalline samples of RBCNO have been synthesized with R = La, Pr and Nd. Attempts to synthesize this structure with the smaller ions Y and Gd have been unsuccessful. The PrBCNO samples show a signature in the magnetization of a magnetic ordering at 12 K. No such magnetic phase transition is observed down to 2 K in the NdBCNO material.