• Journal of the Korean Mathematical Society
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• v.35 no.4
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• pp.1019-1043
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• 1998

In this paper we study some asymptotics for solutions of the Ginzburg-Landau equations with Dirichlet boundary conditions. We consider the solutions ( $u_{\in}$, $A_{\in}$) which minimize the Ginzburg-Landau energy functional $E_{\in}$(u, A). We show that the solutions ( $u_{\in$}$ , $A_{\in}$) converge to some ( $u_{*}$, $A_{*}$) in various norms as the coupling parameter $\in$longrightarrow0.ow0.

• Bulletin of the Korean Mathematical Society
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• v.42 no.3
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• pp.509-520
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• 2005

The author studies the asymptotic behavior of the radial minimizer for a variant of the p-Ginzburg-Landau type functional, in the case of p larger than the dimension, when the parameter tends to zero. The C$^{1, convergence of the radial minimizer is proved. And the estimation of the convergent rate of the minimizer is given.

• Journal of the Korean Mathematical Society
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• v.44 no.3
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• pp.585-603
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• 2007

The author studies the local $H\ddot{o}lder$ convergence of the solution to an evolution equation of p-Ginzburg-Landau type, to the heat flow of the p-harmonic map, when the parameter tends to zero. The convergence is derived by establishing a uniform gradient estimation for the solution of the regularized equation.

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.13-13
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• 2002

• 한국초전도학회:학술대회논문집
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• v.13
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• pp.30-30
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• 2003

• Journal of the Korean Magnetics Society
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• v.1 no.2
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• pp.15-21
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• 1991

The magnetic properties of the $Y_{1}Ba_{2}Cu_{3-x}Sn_{x}O_{7-y}$ superconductor were studied as a function of Sn concentration by utilizing both the vibrating sample magnetometer (VSM) and torque magnetometer. Unlike the cases where Fe and Co were substituted for Cu, the superconducting transition temperature was maintained above 90 K until x reached the value of 0.36. The lower critical field $H_{c1}(T)$ and upper critical field $H_{c2}(T)$ are measured as a function of temperature and external magnetic field, respectively. By aid of these results, $H_{c1}(0)$.($H_{c2}(0)$), the coherence length ${\varepsilon}_{0}$, the penetration depth ${\lambda}_{0}$, and the Ginzburg-Landau parameter k were oqtained. Flux pinning was also observed in the sample.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.206-209
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• 1999

Magnetic and superconducting properties in a series of intermetallic compounds Y$_{1-x}Tb_xNi_2B_2C$ were investigated by measuring the temperature dependent magnetization, M (T), and resitivity, ${\rho}$ (T). As Tb concentration, x, is increased, the superconducting transition temperature, T$_c$, decreases and eventually disappears in the vicinity of x = 0.5 while Neel temperature, T$_N$, appears abruptly near x = 0.4 and increases linearly. Of particular interest is the collision of superconductivity and antiferromagnetism around x = 0.4. The linear decrease of T$_c$ for dilute Tb concentration seems to follow the Abrikosov-Gor'kov behavior, while the decay of T$_c$ below T$_c$ is expected to originate from the effective magnetic field on the conduction electrons. The Ginzburg-Landau theory was phenomenologically constructed to explain this competition of superconducting order parameter and antiferromagnetic order parameter with the multi-band model.

• Progress in Superconductivity and Cryogenics
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• v.16 no.4
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• pp.31-35
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• 2014

The upper critical field ($H_{c2}$) was determined by applying a magnetic field along the ab plane and c axis for two single crystals of $BaFe_{2-x}Ru_xAs_2$ (x=0.48 and 0.75). The anisotropy of the $H_{c2}(0)$, ${\gamma}(0)=H_{c2}{^{ab}}(0)/H_{c2}{^c}(0)$, was ~1.6 for x=0.48 and ~2.3 for x=0.75. The angle-dependent resistance measured below $T_c$ allowed perfect scaling features based on anisotropic Ginzburg-Landau theory, leading to consistent anisotropy values. Because only one fitting parameter ${\gamma}$ is used in the scaling for each temperature, the validity of the ${\gamma}$ value was compared with that determined from ${\gamma}=H_{c2}{^{ab}}/H_{c2}{^c}$. The ${\gamma}$ obtained at a temperature close to $T_c$ was 3.0 and decreased to 2.0 at low temperatures. Comparing to the anisotropy determined for electron- or hole-doped $BaFe_2As_2$ using the same method, the present results point to consistent anisotropy in Ru-doped $BaFe_2As_2$ with other electron- or hole-doped $BaFe_2As_2$.