Characterization of freeze dried boron nanopowders and parameter optimization in MgB2 ex-situ wire production

This paper reports a study to identify optimal synthesis parameters for a pure boron precursor prepared following a patented process developed at CNR-SPIN laboratories, performed in the framework of a collaboration between CNR-SPIN and CERN. B is a precursor which plays a crucial role in MgB2 wire manufacturing, as consequence the synthesis parameters of superconducting phase have been investigated. In this paper, we report results for MgB2 samples synthesized at 870 °C for 1 h under Ar/5% H2 flow and 760 °C for 0.2 h. Magnesiothermic Amorphous Nano-Boron (MANB) and commercial boron nanopowders (purchased from Pavezyum) have been compared in terms of morphological features. MgB2 derived from both sources has been characterized and the superconductive properties in wire form have been compared. Results demonstrate that MANB performance is comparable with nano-boron obtained via gas synthesis.