Nano-sized Al2O3 doping effects on the critical current density of MgB2 superconductors

Fluxoid jump coupled high critical current density of nano-Co3O4doped MgB2

“…Not only the amount of added Mg turnings but the heating rate also controls the amount of Mg/MgO in the end product. In the present study instead of using Mg/MgO as pinning centers in MgB 2 , we added nano-Co 3 O 4 in the pristine We also compare our present results of nano-Co 3 O 4 doped MgB 2 with various other reports [3][4][5][6][7][8] on different nano-particle doped MgB 2 . We found that in most of the nano-particle doped MgB 2 , the high J c is coupled with low field and low temperature fluxiod jumps.…”

“…As far as the volume fraction of the superconductivity is concerned, it is difficult to ascertain the same in the presence of possible high pinning and the PME phenomenon in the present samples. Worth noting is the fact that in various earlier reports [7][8][9][10][11], a similar behavior of FC magnetization in terms of either very weak diamagnetism or PME phenomenon is seen in highly pinned nano-particles doped MgB 2 compounds. as their density, to let them act as effective pinning centers.…”

“…By now a number of articles had appeared on the critical current density of nano particle doped MgB 2 for example nano-SiO 2 [3], nano-Fe [4], nano-diamond [5], nano-SiC [6], nanoTiO 2 [7], nano-Al 2 O 3 [8] and others. Not only the doped nano-particles but various routes of synthesis had also resulted in improved critical current density of this compound [9,10].…”

Correlation between in-field Jc enhancement and grain connectivity in co-doped MgB2 superconductor

“…Slusky et al [10] have shown that Al can aggressively react with MgB 2 , and its substitution into the Mg position leads to a loss of superconductivity. It was found, however, that alumina (Al 2 O 3 ) is more stable in terms of reaction with MgB 2 [11][12][13], and as a dopant, results in low field J c enhancement due to improved grain connectivity. A few successful research efforts have been reported on co-doping [14][15][16] but the effects of simultaneous doping with nano-Al 2 O 3 and SiC on the formation and superconductivity properties of the MgB 2 bulk and wires have not been reported, however, to the best of our knowledge.…”

GeO 2 -added MgB 2 superconductor obtained by Spark Plasma Sintering

“…A significantly lower number of publications are available for the ex-situ routes applied on MgB 2 doped with oxides additions, in general, and doped with metalloid oxides (M a O b , M ¼ Si, Ge, As, Sb, and Te) [22e27] in particular. In the ex-situ routes the starting materials are MgB 2 and the additive [22e24, 28,29]. A successful ex-situ technique is Spark Plasma Sintering (SPS) [22e24, 28,30e32], which provides high density samples (>90%).…”