Settai Rikio

Huge Upper Critical Field and Electronic Instability in Pressure-induced Superconductor CeIrSi3 without Inversion Symmetry in the Crystal Structure

We measured low-temperature electrical resistivity in a magnetic field as a function of pressure, and studied the superconducting property of CeIrSi 3 with a non-centrosymmetric tetragonal structure. CeIrSi 3 is an antiferromagnet with a Neel temperature T N = 5.0 K at ambient pressure, but the antiferromagnetic ordering disappears completely at a pressure P c = 2.25 GPa. Superconductivity appears in a wide pressure region from 1.8 to about 3.5 GPa, with a maximum transition temperature T sc ≃1.6 K at P c * ≃2.63 GPa. At around P c * , the upper critical field H c2 for the magnetic field H along the [0 0 1] direction is not destroyed by spin polarization based on Zeeman coupling but possesses an upturn curvature below 1 K, revealing a divergent tendency of H c2 at P c * , with a huge H c2 (0)≃450 kOe. On the other hand, the upper critical field for H ∥[1 1 0] indicates the tendency of Pauli paramagnetic suppression, with H c2 (0) = 95 kOe at 2.65 GPa. This might be a combined phenomenon between the electr...

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

Magnetic and Superconducting Properties of CeTX3 (T: Transition Metal and X: Si and Ge) with Non-centrosymmetric Crystal Structure

_3

Evidence for Novel Pairing State in Noncentrosymmetric Superconductor CePt3Si: 29Si-NMR Knight Shift Study

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

Observation of Heavy Hole State in CeSb

P_{\rm c}

Specific heat and de haas-van alphen experiments on the heavy-fermion superconductor CePt3Si

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

Magnetic Properties of Single Crystalline RCu2Si2 (R: Rare Earth)

C_{\rm ac}

Fermi surface and Yamaji effect in Sr2RuO4

shows both antiferromagnetic and superconducting transitions at pressures close to

Field-Induced Antiferromagnetism and Upper Critical Field in Pressure-Induced Superconductor CeRhIn5

P_{\rm c}