For conventional and high-Tc superconducting films NbC, Nb3Sn, RBa2Cu3O7 (R=Y, Ho) and Nd1.85Ce0.15CuO4 we have carried out comparative research of the upper critical field Hc2(T) as function of resistivity ϱ. The electron density of states on Fermi level N∗(0) and its change with concentration of radiation defects has been directly evaluated from the dependence of -dHc2/dT on ϱ.

For exceptionally low-defect films of superconducting compound NbC with critical temperature Tc=12 K we have researched the upper critical field Hc2(T) and Tc change caused by high-energy He+ ion irradiation. From the dependence of Hc2 on resistivity ρ the electron characteristics have been evaluated. The parallel critical field H‖(T) of the thin films in a vortex-free state and the Tc degradation mechanism were discussed.

He++ ion irradiation effect on resistive characteristics and upper critical field Hc2(T) of YBa2Cu3O7 and HoBa2Cu3O7 c-axis oriented films has been studied. Analyzing the normal states resistivity modification and Tc degradation with influence F, we estimated the Hc2(T) change in GLAG theory. The -dHc2/dT rise with F has been found. The measured resistive transition midpoint shift TcH-Tc in magnetic field proves higher, then one found from the estimated Hc2(T). So, the transition broadening has been found to be the main effect, determining the TcH-Tc, at least for high fluences.

Caused by magnetic field H broadening δTH of resistive transition width has been measured for high-Tc c-oriented films irradiated by He++ ions. Found relation δTH=B·H23 with the coefficient B depending on fluence is interpreted in terms of flux motion and order parameter fluctuations. The δTH anisotropy proves low sensitive to then irradiation. Decrease of the transition midpoint shift anisotropy is considered as a display of Hc2 anisotropy lowering.

The described magnetron system allows coatings to be deposited on cylindrical surfaces. The system provides for uniform rotation of the specimen and its heating by current to 900-degrees-C, and shear stresses and associated deformations are not produced in the specimen. The unit is simple to build and easily dismounted for cleaning.

We have investigated upper critical field Hc2 (T) in correlation with resistivity ϱ of HoBa2Cu3O7-x and YBa2Cu3O7-x polycrystal and single-crystal films, including ones irradiated by ions He++. The results were considerded mainly in terms of electronic structure and percolation model.

Superconducting films of YBa2Cu3O7 was irradiated by He2+ions. After fluences F > 2 · 1016 ion · cm−2 Tc < 4.2 K. Tc and Jc of these films more sensitive to irradiation than Nb3Sn films.