Electrical resistivity ρ, magnetic susceptibility χ, magnetization M and specific heat measurements are reported on a singlecrystalline sample of CePd5Al2, showing successive antiferromagnetic orderings at TN1=4.1 K and TN2=2.9 K. The temperature dependence of ρ shows a Kondo metal behavior with large anisotropy, ρc/ρa =3.2 at 20 K, and opening of a superzone gap along the tetragonal c-direction below TN1. Both TN1 and TN2 gradually increase with applying pressure up to 2.5 GPa. The data of χ(T ) and M (B) in the paramagnetic state were analyzed using a crystalline electric field (CEF) model. It led to a Kramers doublet ground state with wave functions consisting primarily of˛± 5 2¸, whose energy level is isolated from the excited states by 230 and 300 K. This CEF effect gives rise to the large anisotropy in the paramagnetic state. In the ordered state, the uniaxial magnetic anisotropy is manifested as Mc/Ma=20 in B=5 T and at 1.9 K, and χc/χa=25 in B=0.1 T and at 4 K. This huge uniaxial magnetic anisotropy in the antiferromagnetic states can be interpreted in terms of isotropic magnetic interaction among the Ce 3+ moments governed by the strong CEF. In powder neutron diffraction experiments, magnetic reflections were observed owing to the antiferromagnetic ordered states below TN1, however, no additional reflection was found below TN2.

We have investigated the effect of carbon on the coercivity and microstructure in finegrained Nd-Fe-B sintered magnets fabricated by the press-less sintering method. The coercivity of the sample with the carbon content of 730 ppm (low-C) was 1.59 T while that of the sample with 1500 ppm (high-C) was 1.44 T in the as-sintered state. The low-C sample exhibited a larger coercivity increase by a post-sinter annealing, reaching the highest coercivity of 1.85 T while the high-C sample reached a lower coercivity of 1.54 T. Detailed microstructure investigations using scanning electron microscopy, scanning transmission electron microscopy and atom probe tomography revealed that the high carbon caused the formation of a Nd-carbide with a tetragonal structure and the reduction in the volume fraction of an -Nd phase at triple junctions. This in turn decreased the Nd+Pr concentration in thin Nd-rich grain boundary phase, resulting in the lower coercivity.

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We have investigated the effect of pressure on the magnetic and structural properties of the frustrated heavy-fermion antiferromagnet YbAgGe in an extended pressure range up to 20 GPa using electrical resistivity and x-ray diffraction, respectively. We find that with increasing pressure, the magnetic ordering temperature ͑T m ͒ first increases rapidly, passes through a maximum ͑T m = 5.4 K at 6.8 GPa͒, and then drops toward zero for p above 16 GPa, while the structure remains unchanged up to about 20 GPa. We attribute the anomalous pressure dependence of T m to a complex interplay between the Kondo effect, Ruderman-Kittel-Kasuya-Yosida interactions and the geometrical frustration of the magnetic interactions of the Yb moments in the Kagomélatticelike structure of YbAgGe. We further discuss the competition between geometrical frustration and longrange magnetic order together with the possible occurrence of a pressure-induced second quantum critical point in YbAgGe.