Transport and Cu NMR studies of charge and spin dynamics in PrBa2Cu4O8

The charge and spin dynamics in PrBa₂Cu₄O₈ are investigated by means of transport and Cu NMR measurements. The magnetoresistance was found to be very small at high temperatures and increase rapidly with decreasing temperature below 100 K, which may be ascribed to the dimensional crossover from one to two dimensions in the charge transport in the CuO double chains. While the NMR signal from the chain Cu sites persists down to 4.2 K without any appreciable line broadening, the signal from the planar Ce sites disappears below 250 K indicating the long-range antiferromagnetic order of plane Cu moments. This is consistent with the view of metallic conduction along the quasi one-dimensional CuO chains.