Magnetic ordering and chain transport of ${\mathrm{PrBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$

The effects of Fe, Co, and Ni substitution on the structural, magnetic, and electrical properties of ${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$ have been investigated by means of powder x-ray diffraction, magnetization, and electrical-resistivity measurements. All three systems ${\mathrm{PrBa}}_2$(${\mathrm{Cu}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{M}}_{\mathit{x}}$ ${)}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$ (M=Fe, Co, and Ni) exhibit an orthorhombic-tetragonal transition at about x=0.025 for Fe and Co, and x=0.05 for Ni. The magnetic ordering temperature ${\mathit{T}}_{\mathit{N}}$ of ${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$ is reduced by the doping of Fe, Co, and Ni with the depression rate ${\mathit{dT}}_{\mathit{N}}$/dx∼0.65, 0.75, and 0.45 K/at. %, respectively. The doping of Fe or Co has a larger effect than Ni on the increase of room-temperature resistivity. Combining these results with those observed previously in Zn- and Ga-doped ${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$, it is interpreted that the Cu-O chain is considered to play a crucial role in the magnetic-coupling mechanism of ${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{y}}$.