TY - JOUR
T1 - Study of magnetization and pinning mechanisms in MgB2 thin film superconductors
T2 - Effect of heavy ion irradiation
AU - Gupta, Anurag
AU - Narayan, H.
AU - Astill, D.
AU - Kanjilal, D.
AU - Ferdeghini, C.
AU - Paranthaman, M.
AU - Narlikar, A. V.
PY - 2003/8
Y1 - 2003/8
N2 - We report magnetization studies on MgB2 superconducting thin films in a temperature range 4.2-40 K and magnetic field range 0-6 T. Thin films prepared by both pulsed laser deposition (PLD) and electron beam evaporation (EBE) methods were investigated. In addition, both films were studied before and after heavy ion irradiation by 200 MeV Ag ions with a dose of 1011 ions cm-2. Variation of sweep rates during the measurement of the magnetization loop reveals the presence of flux creep in both films. The PLD film, after irradiation, shows a severe degradation of Tc, critical current densities (Jc) in low fields and irreversibility line (B*(T)). In contrast, the EBE film shows a slight enhancement in TC, and nearly no change in JC(B) and the position of irreversibility line after irradiation. For both pristine films, the obtained volume pinning forces Fp versus reduced field b = B/B* shows a good scaling for T ≤ 10 K, which matches well with the theoretical curve based on the flux line shear (FLS) pinning model. These and other results can be interpreted in terms of grain boundaries in MgB 2 films acting as FLS channels.
AB - We report magnetization studies on MgB2 superconducting thin films in a temperature range 4.2-40 K and magnetic field range 0-6 T. Thin films prepared by both pulsed laser deposition (PLD) and electron beam evaporation (EBE) methods were investigated. In addition, both films were studied before and after heavy ion irradiation by 200 MeV Ag ions with a dose of 1011 ions cm-2. Variation of sweep rates during the measurement of the magnetization loop reveals the presence of flux creep in both films. The PLD film, after irradiation, shows a severe degradation of Tc, critical current densities (Jc) in low fields and irreversibility line (B*(T)). In contrast, the EBE film shows a slight enhancement in TC, and nearly no change in JC(B) and the position of irreversibility line after irradiation. For both pristine films, the obtained volume pinning forces Fp versus reduced field b = B/B* shows a good scaling for T ≤ 10 K, which matches well with the theoretical curve based on the flux line shear (FLS) pinning model. These and other results can be interpreted in terms of grain boundaries in MgB 2 films acting as FLS channels.
UR - http://www.scopus.com/inward/record.url?scp=0042967632&partnerID=8YFLogxK
U2 - 10.1088/0953-2048/16/8/322
DO - 10.1088/0953-2048/16/8/322
M3 - Article
AN - SCOPUS:0042967632
SN - 0953-2048
VL - 16
SP - 951
EP - 955
JO - Superconductor Science and Technology
JF - Superconductor Science and Technology
IS - 8
ER -