W. N. Kang

Superconducting properties of well-shaped MgB2 single crystals

We report measurements of the transport and the magnetic properties of high-quality, sub-millimeter-sized

Effect of sintering temperature under high pressure on the superconductivity of MgB2

{mathrm{MgB}}_{2}

Temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high-temperature and high-pressure condition

single crystals with clear hexagonal-plate shapes. The low-field magnetization and the magnetic hysteresis curves show the bulk pinning of these crystals to be very weak. The Debye temperature of

Prominent bulk pinning effect in the MgB 2 superconductor

{ensuremath{Theta}}_{D}ensuremath{sim}1100 mathrm{K},

Far-infrared transmission studies of a c -axis-oriented superconducting MgB 2 thin film

obtained from the zero-field resistance curve, suggests that the normal-state transport properties are dominated by electron-phonon interactions. The resistivity ratio between 40 K and 300 K was about 5, and the upper critical field anisotropy ratio was

Universal scaling of the Hall resistivity in MgB 2 superconductors

3.0ifmmodepmelsetextpmfi{}0.2

Complicated nature of the gap in MgB 2 : Magnetic-field-dependent optical studies

at temperatures around 32 K.

Angle-resolved soft x-ray spectroscopy study of the electronic states of single-crystal MgB 2

We report on the effect of sintering temperature on the superconductivity of MgB2 pellets prepared under a high pressure of 3 GPa. The superconducting properties of the nonheated MgB2 were poor. However, as the sintering temperature increased, the superconducting properties were vastly enhanced, which was demonstrated by the narrow transition width for the resistivity and the low-field magnetization. The observed surface morphology using scanning electron microscopy showed that these changes were closely related to changes in the microscopic level such as the connectivity of the grains.

High-resolution transmission electron microscopic observation of highly dense MgB2 superconductors

We report the temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high-temperature and high-pressure condition. The superconducting transition width for the resistivity measurement was about 0.4 K, and the low-field magnetization showed a sharp superconducting transition with a transition width of about 1 K. The resistivity in the normal state roughly followed T2 behavior with smaller residual resistivity ratio (RRR) of 3 over broad temperature region above 100 K rather than reported T3 behavior with larger RRR value of ∼20 in the samples made at lower pressures. Also, the resistivity did not change appreciably with the applied magnetic field, which was different from previous report. These differences were discussed with the microscopic and structural change due to the high-pressure sintering.

Interband Scattering in MgB2

We report the magnetic-field dependence of the irreversible magnetization of the recently discovered binary superconductor