Effects of surface damage on critical current density in MgB2 thin films

Effects of irradiation on superconducting properties of small-grained MgB2 thin films

“…The small decrease in low-field J c for irradiated MB430 can be thought to be due to the giant proximity effect between the irradiated and unirradiated layers. [50,51] 127402-4 6, indicating that the residual sharp peak of f p (b) at low fields in the irradiated MB430 is associated with the unirradiated region. Our findings can provide useful information for designing radiation resistant MgB 2 because grain boundaries in metallic MgB 2 superconductors can be acted as an effective sink of irradiation-induced defects, thus irradiation tolerance of MgB 2 can be enhanced by decreasing grain size.…”

Enhancement in High-Field Jc Properties and the Flux Pinning Mechanism of ZnO-Buffered MgB2 Films

“…Several studies have been conducted to enhance the pinning properties of MgB 2 at high magnetic fields by chemical doping, − grain size reduction, − and particle irradiation. − For the thin-film form of MgB 2 , various kinds of buffer layers have been tried. − The use of ZnO as a buffer layer on metallic substrates has yielded promising results. ZnO buffer layers with thicknesses ranging from tens to hundreds of nanometers do not significantly degrade the T c values while suppressing delamination and hindering unwanted reactions between MgB 2 and the metal substrates. , As the ZnO buffer layer thickens, the local structure is distorted owing to the atomic bond length variation between Mg–B and Mg–Mg, which leads to the T c fluctuation.…”

“…Several studies have been conducted to enhance the pinning properties of MgB 2 at high magnetic fields by chemical doping, 10 − 15 grain size reduction, 16 − 18 and particle irradiation. 19 − 23 For the thin-film form of MgB 2 , various kinds of buffer layers have been tried. 24 − 29 The use of ZnO as a buffer layer on metallic substrates has yielded promising results.…”