The inter-grain connectivity (AF) of the samples varies between 11%–20%. The resistive superconducting onset Tcon ∼ 38.6 ± 0.3 K and offset (where ρ goes to zero) Tc0 ∼ 38.1 ± 0.3 K of the samples stay nearly unchanged. Detailed investigations of X-ray diffraction, magnetization (M), and resistivity (ρ) as a function of temperature (T) and field (B) in the range 5–300 K and 0–8 T are carried out in all the samples. % addition of various non-carbon based additives like nano-Ag, nano-Ni, and YBCO are synthesised by the in-situ route. MgB2 samples with stoichiometric composition, excess Mg (5 wt.
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113, 036908 (2013)), where we reported comprehensive analysis of inter-grain connectivity (AF), pinning, percolation threshold (Pc), and anisotropy (γ) in a series of ex-situ processed MgB2, we address the same issues in in-situ processed samples. Of 18.1 K and a critical current density J The as-deposited films have so far a superconducting transition temperature T Microscopic analyses yield nanocrystalline dense films with high film stresses. With the so-called aerosol deposition technique, MgBįilms were prepared on Hastelloy substrates with commercially available ex situ-prepared MgBĪt 4 K and 1 T). Such a technique might give rise to new tapes with higher filling factors compared to the standard processed tapes. We present a new high-deposition-rate coating technique that allows us to produce at room temperature long thick films of MgB The contributions of the sintering conditions on fP for both synthesis methods were analyzed. Microstructural characterization and flux pinning (fP) analysis revealed the possibility of refined MgO inclusions and MgB4 phase as new pinning centers, which greatly contributed to the Jc-B properties. In addition, the in situ method showed very minimal impurity with a corresponding improvement in density and Jc-B characteristics for the sample optimized at 750 ☌. The sample that underwent SPS treatment for a short time at 850 ☌ showed higher density and less impurity phase in the bulk, which improved the Jc-B properties. In the ex situ method, the degradation of MgB2 due to pyrolysis was more severe at temperatures higher than 850 ☌. As a result, we found that higher density with suppressed particle growth and suppression of the formation of coarse particles of MgB4 and MgO were found to be effective in improving the Jc-B characteristics. We investigated the relationship between sintering conditions (temperature and time) and Jc-B using two methods, ex situ (sintering MgB2 synthesized powder) and in situ (reaction sintering of Mg and B powder), respectively. In this study, high-density magnesium diboride (MgB2) bulk superconductors were synthesized by spark plasma sintering (SPS) under pressure to improve the field dependence of the critical current density (Jc-B) in MgB2 bulk superconductors.
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