Metal-Doped MgB2 by Thermal Explosion: A TRXRD Study

Resumo

The work aimed at preparation of the MgB₂ doped with alloying metals (Al, Cu, Ag, Zn) by SHS in a mode of thermal explosion. The measured combustion temperatures fell within the range 940–1030°С. Detailed XRD analysis has shown that, among other selected metals, it is solely Al that can enter the MgB₂ lattice. According to time-resolved XRD results, the formation of final product (Mg, Al)B₂ in the Mg–Al–B system involved no intermediate phases. But in the Mg–Cu–B system, the volume reaction additionally yielded MgB₄, Cu₂Mg, and CuMg₂ due to the presence of the liquid phase. In final products, the agglomerates of MgB₂ grains had a size of 500–1000 nm, while the size of Cu₂Mg and CuMg₂ inclusions was within 0.5–2 μm.