Tateiwa Naoyuki

Unconventional Heavy-Fermion Superconductivity of a New Transuranium Compound NpPd5Al2

We succeeded in growing a new transuranium compound NpPd 5 Al 2 with the tetragonal crystal structure by the Pb-flux method, and measured the electrical resistivity, specific heat, magnetic susceptibility and magnetization. NpPd 5 Al 2 is found to be a paramagnetic heavy-fermion superconductor with strong coupling Δ C /γ T c = 2.33 [ T c =4.9 K and γ= 200 mJ/(K 2 ·mol)]. The upper critical field H c2 at 0 K is large and highly anisotropic: H c2 (0) =37 kOe for H ∥[100] and H c2 (0) =143 kOe for H ∥[001]. H c2 is found to be strongly suppressed by the magnetic field, and the magnetization curve indicates a step-like increase at H c2 , which are due to the paramagnetic effect. The low-temperature electronic specific heat approximately follows the T 3 -dependence, indicating the existence of point nodes in the energy gap. The d -wave superconductivity with point nodes is most likely realized in this compound.

Strong-Coupling Superconductivity of CeIrSi3 with the Non-centrosymmetric Crystal Structure

We studied the pressure-induced superconductor CeIrSi

Effect of Pressure and Magnetic Field on the Superconducting State of a Heavy Fermion Superconductor NpPd5Al2

_3

High-Quality Single Crystal Growth and Unique Electronic States under Magnetic Field and Pressure in Rare Earth and Actinide Compounds

with the non-centrosymmetric tetragonal structure under high pressure. The electrical resistivity and ac heat capacity were measured in the same run for the same sample. The critical pressure was determined to be

Non-magnetic to Magnetic Transition under High Pressure in Narrow-Gap Semiconductor β-US2

P_{\rm c}

Effect of Pressure on Magnetism of UIrGe

= 2.25 GPa, where the antiferromagnetic state disappears. The heat capacity

Heavy Fermion Superconductivity with the Strong Pauli Paramagnetic Effect on NpPd5Al2

C_{\rm ac}

Thermodynamics Investigation on Pressure-induced Superconductor CeNiGe3 by ac Calorimetry

shows both antiferromagnetic and superconducting transitions at pressures close to

Single Crystal Growth and Magnetic Properties of SmCu2Ge2

P_{\rm c}

Magnetic-Field-Induced Metallic State in β-US2

. On the other hand, the superconducting region is extended to high pressures of up to about 3.5 GPa, with the maximum transition temperature