Magnetic order of Pr in ${\mathrm{PrBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_7$

The magnetic order of Pr in nonsuperconducting ${\mathrm{PrBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ has been studied by specific-heat, susceptibility, and neutron-diffraction measurements. The basic ordering consists of a simple antiferromagnetic arrangement, with a saturated moment of 0.24${\mu }_B$ and a Néel temperature $T_N$ of ∼17 K, which is two orders of magnitude higher than expected from either dipolar or Rudeman-Kittel-Kasuya-Yosida interactions alone. The small moment, along with the large value of the low-temperature electronic specific-heat coefficient γ of 196 mJ/mol ${\mathrm{K}}^2$, suggests that there is substantial f-electron character at the Fermi level.