MAGNETOTRANSPORT AND MAGNETISM IN SINGLE-CRYSTAL PRBA2CU3O7-DELTA

The PrBa2Cu3O7-delta (Pr 123) system is known to exhibit antiferromagn etic ordering of the Cu spins in the Cu-O planes and chains, in additi on to the observed antiferromagnetism due to the ordering of the Pr io ns. The antiferromagnetism of the Cu-O planes is generally associated with the insulating nature of transport in Pr 123 and electrical condu ction is believed to result through ''hopping'' transport between diso rdered Cu-O chain segments. However, the possible effects of magnetic ordering in the Cu-O chains on transport properties have not been disc ussed. If the Cu-O chains play a dominant role in the electrical trans port (as suggested by many of the popular theories), then the magnetic ordering of the chains should also be seen in the transport propertie s. We present magnetization and magnetotransport measurements on singl e crystal Pr 123 samples which suggest that the magnetism associated w ith the Cu-O chains does indeed mediate transport in this system. Thes e results confirm that the chains play a significant role in the trans port properties and underscore the need for further study of the inter play between magnetism and transport in Pr 123.