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The thermal properties are one of the key parameters to control phase purity and microstructure of polycrystalline materials. The melting point of the iron-based BaFe2As2 superconductor (Ba122), which foresees high-field applications, remains controversial. In this work, thermogravimetry-differential scanning calorimetry measurements (TG-DSC) of undoped and Co-doped Ba122 were carried out. Mixtures of elemental metals and pre-reacted Ba122 powders were prepared to investigate the thermal responses during in situ and ex situ synthesis routes, respectively. In addition, the phases and microstructures of the quenched samples were evaluated to elucidate the observed exothermic/endothermic peaks. Our results suggest that the melting point of Ba122 is ~1300{deg}C.
In DC and AC practical applications of MgB2 superconducting wires an important role is represented by the material sheath which has to provide, among other things, a suitable electrical and thermal stabilization. A way to obtain a large enough amount
The two most common types of MgB2 conductor fabrication technique - in-situ and ex-situ - show increasing conflicts concerning the connectivity, an effective current-carrying cross-sectional area. An in-situ reaction yields a strong intergrain coupli
We have fabricated a series of iron-sheathed superconducting wires prepared by the powder-in-tube technique from (MgB_2)_{1-x}:(Mg+2B)_x initial powder mixtures taken with different proportions, so that x varies from 0 to 1. It turned out that ex-sit
Two types of MgB2 films were prepared by pulsed laser deposition (PLD) with in situ and ex situ annealing processes respectively. Significant differences in properties between the two types of films were found. The ex situ MgB2 film has a Tc of 38.1K
MgB2 monofilamentary nickel-sheated tapes and wires were fabricated by means of the ex-situ powder-in-tube method using either high-energy ball milled and low temperature synthesized powders. All sample were sintered at 920 C in Ar flow. The milling