Fast formation and superconductivity of MgB2 thick films grown on stainless steel substrate

Abstract

The fabrication, characterisation, and superconductivity of MgB 2 thick films grown on stainless steel substrate were studied. XRD, SEM, and magnetic measurements were carried out. It was found that the MgB 2 thick films can be fast formed by heating samples to 660 o C then immediately cooling down to room temperature. XRD shows above 90% MgB 2 phase and less than 10 % MgO. However, the samples sintered at 800 o C for 4 h contain both MgB 4 and MgO impurities in addition to MgB 2 . The fast formed MgB 2 films appear to have a good grain connectivity that gives a J c of 8 x 10 4 A/cm 2 at 5 K and 1 T and maintained this value at 20 K in zero field.2

Effect of grain size and doping level of sic on the superconductivity and critical current density in MgB/sub 2/ superconductor

“…It has been reported that the MgB can be formed by in-situ reaction between magnesium and amorphous boron in a very short time, as little as a few minutes at temperatures just above the melting point of magnesium [16], [17]. Furthermore, the samples sintered at temperatures above 750 C for only a few minutes are as good as those sintered for a long time.…”

Flux Jump Behaviors and Mechanism of MgB2 Synthesized by the Non-special Atmosphere Synthesis

“…In addition, there are many impurities (mainly Mg) on the surface of the film, which are formed during the synthesis of MgB 2 . Consequently, the giant flux jump of MgB 2 films is reduced further by these impurities [9,15]. Treiber et al, however, insisted that there are still flux jumps in the film around 12 K, even though their behavior was different from the jumps observed below 10 K [16].…”

Superconducting properties of SiC-buffered-MgB2tapes

“…Attempts to fabricate MgB 2 tapes with wide variety of metal substrates [7][8][9] along with the insertion of different dopants [10,11] and buffer layers [11,12] into MgB 2 tapes have been vigorously made in the past several years. Out of different processing conditions, MgB 2 grown on Hastelloy tape seems to have a good prospect in the industry due to the Hastelloy's flexibility and its low corrosiveness [8,[13][14].…”