A study was made, of 3 c-axis oriented thin films, which showed that the upper critical field anisotropy ratio, HC2||/HC2, was 1.8 to 2.0; with the ratio increasing with higher resistivity. Measurements of the magnetic field-temperature phase diagram showed that flux-pinning disappeared at about 0.8HC2(T) in non-textured samples. The HC2||(0) value was strongly enhanced, by alloying, to 39T for the highest resistivity film. This was more than twice that seen in bulk samples.

Electronic Anisotropy, Magnetic Field-Temperature Phase Diagram and their Dependence on Resistivity in c-Axis Oriented MgB2 Thin Films. S.Patnaik, L.D.Cooley, A.Gurevich, A.A.Polyanskii, J.Jiang, X.Y.Cai, A.A.Squitieri, M.T.Naus, M.K.Lee, J.H.Choi, L.Belenky, S.D.Bu, J.Letteri, X.Song, D.G.Schlom, S.E.Babcock, C.B.Eom, E.E.Hellstrom, D.C.Larbalestier: Superconductor Science and Technology, 2001, 14, 315-9