Influence of the starting composition on the structural and superconducting properties of MgB2 phase

Abstract

We report the preparation of Mg${}_{1-x}$B${}_2$ (0$\le$x$\le$0.5) compounds with the nominal compositions. Single phase MgB${}_2$ was obtained for x=0 sample. For 0$<$x$\le$0.5, MgB${}_4$ coexists with "MgB${}_2$" and the amount of MgB${}_4$ increases with x. With the increase of x, the lattice parameter $c$ of "MgB${}_2$" increases and the lattice parameter $a$ decreases, correspondingly T${}_c$ of Mg${}_{1-x}$B${}_2$ decreases. The results were discussed in terms of the presence of Mg vacancies or B interstitials in the MgB${}_2$ structure. This work is helpful to the understanding of the MgB${}_2$ films with different T${}_c$, as well as the Mg site doping effect for MgB${}_2$.

11 pages, 4 figures

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Cited by in corpus (6)

• Synthesis and Stoichiometry of MgB2
• Enhancement of Critical Current Density in low level Al-doped MgB2
• Study of Ag and Cu / MgB2 powder-in-tube composite wires fabricated by in-situ reaction at low temperature
• Crystal growth and characterization of MgB2: Relation between structure and superconducting properties
• Influence of Mg deficiency in MgB2 single crystals on crystal structure and superconducting properties
• Heat capacity of mesoscopically disordered superconductors:implications to MgB${}_2$