Study of superconducting properties of MgB2
arXiv:cond-mat/0207658 · doi:10.1103/PhysRevB.67.094507
Abstract
We synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of policrystalline MgB_2 samples has been measured in a temperature range between 2 and 60 K in magnetic field up to 6 T. The measurement gave the coefficient of the linear term in the electronic specific heat, gamma = 3.51 mJ/K^2 mol, and the jump of the specific heat, 2.8 mJ/K^2 mol at 38.5 K. It is shown from the analysis of the specific heat that the electronic specific heat in the superconducting state differs largely from the conventional BCS weak coupling theory. From the results of measurements of the magnetic properties on single crystal samples, we found a sharp superconducting transition at 38 K with transition width Delta Tc = 0.8 K and the superconducting anisotropy ratio gamma increasing from about 1 near Tc to 4.0 at 25 K.
arXiv comment6 pages, 10 figures
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Cited by in corpus (5)
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- Surface Contribution to the Superconducting Properties of MgB2 Single Crystals
- Characterization of high-quality MgB2(0001) epitaxial films on Mg(0001)
- Strong phase coherence and vortex matter in a fractal system with proximity-induced superconductivity