Synthesis and Characterization of MgB2–MgO Composite Superconductor

MgB2-MgO Compound Superconductor

“…These characteristics indicate that MgB 2 has the potentiality of superconductive applications in high-power field and electronic devices and will be the best material to replace the traditional niobium (Nb) and Nb alloy superconductors working at the liquid helium temperature. (Zhang et al, 2009) Magnesium oxide (MgO) has the cubic crystal structure with a lattice parameter a=4.123 Å, which is close to one of MgB 2 . Considering that MgO phase is easily to be formed in the process of preparing MgB 2 superconductor and a small amount of MgO contamination will not degrade evidently the superconductivity of MgB 2 , the authors are interested in studying MgB 2 -MgO Compounds.…”

“…Such crystallite size and distribution indicate this is an ideal composite for studying the boundary and grain connection properties of MgB 2 superconductor. (Zhang et al, 2009; The resistance of the composite as a function of temperature was measured from 10 K to 300 K by the standard four-probe method in a close-cycle refrigeration system. Fig.…”

“…Temperature dependence of the real component (χ') and the imaginary one (χ") of ac magnetic susceptibility at the ac field amplitude 10 Oe and frequency 777 Hz. The magnitude of susceptibility was not normalized in this figure (Zhang et al, 2009). (Zhang et al, 2009; …”

“…The magnitude of susceptibility was not normalized in this figure (Zhang et al, 2009). (Zhang et al, 2009; …”

“…the metal-insulator mixture. According to measured mass density and the scanning electron microscope (SEM) image of the composite (Zhang et al, 2009), we noticed that the composite is not dense and the host phase is an insulator (MgO) with crystal grain sizes of far smaller than ones of the metal phase (MgB 2 ). Both of MgO particles and the holes in the composite can be regarded as an insulating background for superconducting MgB 2 grains to embed.…”