Magnetic order of Pr inPrBa2Cu3

W. H. Li

¹

,

J. W. Lynn

²

,

S. Skanthakumar

³

et al.

PrBa2Cu3O7−y investigated by141Pr Mössbauer spectroscopy

“…there must be a wide distribution in hyperfine fields. Such a distribution may be possible, for a distribution in the direction of the exchange has been observed in Yb-doped PrBa2Cu307_y with 17~ M6ssbauer spectroscopy [8], but it is in contradiction to the results of Li et al [5].…”

“…1. This analysis gives a hyperfine field of 29(3) T. This is only 10% of the free ion value of 326 T and less than that of PRO2, indicating for this sample a small magnetic moment of 0.32(3)/.% only, which is about half the value found by Li et al [5]. However, the resonance absorption effect we observe at 4.2 K is less than that at 25 K, in sharp contrast to PRO2.…”

“…The neutron scattering experiments of Li et al [5] indicated fully three-dimensional antiferromagnetic ordering of Pr in PrBa2Cu3OT_y , but another neutron scattering measurement failed to reproduce magnetic ordering down to 10 K [6].…”

Thermodynamic properties of superconducting and non-superconducting Pr2Ba4Cu7O15-δ compounds with metallic double chains

“…In the as-sintered sample, a typical anomaly in χ occurs near 17 K. This anomaly is associated with an antiferromagnetic transition of the Pr sublattice, as previously reported in Pr123 and Pr124 systems. 5,6 On the contrary, the 48-h-reduced sample becomes superconductive below T on c = 26.5 K. The superconducting volume fraction f was estimated from the magnetic data taken at 10 mT by f = χ · ρ/4π × 100, where χ and ρ denote the magnetic susceptibility per unit weight and the sample density (5.3 g/cm 3 ), respectively. As displayed in the inset of Fig.2 (b), the volume fraction reaches ∼30 % at 4 K, indicating bulk superconductivity.…”

“…4 The carrier concentration of doped double chains of Pr124 is difficult to vary, because it is thermally stable up to high temperatures. In addition, Pr ions in both Pr123 and Pr124 become antiferromagnetic ordered at the antiferromagnetic transition temperature T N = 17 K. 5,6 The compound Pr 2 Ba 4 Cu 7 O 15−δ (Pr247) is an intermediate between Pr123 and Pr124. In this compound, CuO single-chain and double-chain blocks are alternately stacked along the c-axis 7,8 (see Fig.1).…”