THE PREPARATION AND ELECTRONIC STRUCTURE OF PrBa 2 Cu 3 O 7-δ

Single phase samples of PrBa 2 Cu 3 O 7-δ with orthorhombic structure were prepared by solid State reaction method. Resistance measurement was performed by a standard dc four-probe technique. It is found that the resistance exhibits semiconductor-like behavior. Results of XPS measurement indicate obviously the existence of Pr 4+ in PrBa 2 Cu 3 O 7-δ . Finally, the band structure was used to discuss the reasor why PrBa 2 Cu 3 O 7-δ does not show superconductivity.