BaZrO3 dopant interactions during MgB2 wire formation by modified internal magnesium diffusion process


Undoped and BaZrO3 nanopowder-doped MgB2/Nb/Cu single filament wires were prepared by modified internal magnesium diffusion (IMD) process using 0, 2 and 5 wt% BaZrO3 addition in amorphous B powder. Superconducting MgB2 phase was formed during heat treatment at temperatures from 650 to 670 °C. The wire microstructure was analysed using XRD, SEM, TEM and EDS to study BaZrO3 dopant interaction with Mg and B precursors during the heat treatment and effect of dopant on MgB2 superconductor. The BaZrO3 nanopowder decomposed and its products reacted with Mg and B producing relatively large BaB6 grains and nanograins of ZrB2 and MgO phases which were not detected by conventional XRD measurements due to their low grain size. Measured MgB2 lattice parameters varied with the dopant addition and heat treatment temperature. Different possible origins of MgB2 lattice deformation were discussed, and it was shown that Zr substitution in MgB2 lattice could not cause this deformation.

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taken from a nanograin conglomerate part; the markers correspond to positions of diffraction rings of phases according to powder diffraction database PDF2

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The authors thank Dr. B. Brunner and Dr. M. Kulich for doped and undoped MgB2 wires. We thank J. Scheiter from Institute for Metallic Materials, Leibniz-Institute for Solid State and Materials Research (IFW), Dresden, Germany, for TEM specimen preparation. This work was supported by the Slovak Scientific Agencies Agentúra pre podporu výskumu a vývoja (project APVV-18-0271) and Vedecká grantová agentúra MŠVVaŠ a SAV (project VEGA 2/0140/19).


This work was supported by the Slovak Scientific Agencies APVV and VEGA under the following projects: VEGA 2/0140/19 and APVV-18–0271.

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Alica Rosová contributed to the conceptualization, investigation, data curation, writing and visualization. Igor Maťko was involved in the investigation and visualization. Edmund Dobročka contributed to the investigation.

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Correspondence to A. Rosová.

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Rosová, A., Maťko, I. & Dobročka, E. BaZrO3 dopant interactions during MgB2 wire formation by modified internal magnesium diffusion process. Appl. Phys. A 127, 152 (2021).

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  • MgB2
  • Microstructure; superconductors; IMD
  • Doping
  • Strain