Magnetic Properties of Filled Skutterudite Phosphides with Heavy Lanthanides Synthesized under High Pressure

Abstract

Filled skutterudite phosphides with heavy lanthanides LnT 4P12 (Ln=Gd, Tb, Dy, T =Fe, Ru, Os) were prepared at high temperatures and high pressures. The magnetic properties of these compounds were studied in detail through electrical resistivity ρ(T), magnetic susceptibility, magnetization, specific heat, and thermoelectric power S(T) measurements. The filled skutterudite DyRu4P12 was synthesized for the first time. DyRu4P12 shows an antiferromagnetic transition at TN =15 K. The dramatic increase at TN observed in ρ(T) and S(T) suggest the formation of a superzone gap due to Fermi surface nesting. All the compounds undergo a ferromagnetic or antiferromagnetic transition at low temperatures except TbOs4P12. TbOs4P12 is found to be paramagnetic down to 2 K. The magnetic ordered states of filled skutterudite phosphides containing heavy lanthanides are discussed.

Transport properties in filled skutterudite GdRu4P12

“…Figure 2 shows the H-dependence of (a) the magnetization (M ), (b) the Hall resistivity (ρ H ) and (c) the transverse magnetoresistivity (ρ) at three selected temperatures. Both ρ and ρ H exhibit a clear kink at a critical field H c (∼ 6.3 T for 2 K and ∼ 5.9 T for 10 K), which is consistent with the reported phase diagrams [6,9]. At 25 K and in the field induced paramagnetic phase at 10 K, ρ monotonically decreases up to 9 T, reflecting the reduction of conduction electron scattering by magnetic fluctuation.…”

Thermoelectric properties of YbxCo4Sb12prepared under high pressure

“…The experimental methods used were the same as those described in a previous paper. 16,22) After being placed in the apparatus, each sample was pressed at up to 2 GPa and kept at 600 °C for 120 min.…”

Thermal Properties of Filled Skutterudite PrOs4P12

“…NdOs 4 P 12 and GdOs 4 P 12 show a ferromagnetic transition at 1.15 K and 5 K, respectively. 19,20) S (T ) of PrOs 4 P 12 at room temperature is 12.7 µV/K and reduces on cooling below 150 K. The curvature of S (T ) in all compounds becomes large around 100-130 K. One possible explanations for this is the proximity to Θ D /5, i.e., the expected phonon drag peak taking into account the reported value of Θ D = 523 K for Ln = La. For PrOs 4 P 12 , the behavior of S (T ) is different from that for LaOs 4 P 12 .…”