Measurements of the critical current density were conducted on MgB2 films with the thickness in the range of 0.2 to 1.1µm. The films were prepared by a combined method of chemical vapour deposition and Mg diffusion. The thinnest film had critical current density over 26MA/cm2 at 15K in zero field. As film thickness was increased, JC decreased to 4.9MA/cm2. Scanning electric microscopy analyses indicated a progressive surface deterioration with the increase of film thickness that led to the fall in JC.

Correlation between Film Thickness and Critical Current Density of MgB2 Films. S.F.Wang, Z.Liu, Y.L.Zhou, Y.B.Zhu, Z.H.Chen, H.B.Lu, B.L.Cheng, G.Z.Yang: Superconductor Science and Technology, 2004, 17, 1126-8