论文信息 - Dependence of critical temperature and resistivity of thin film Nb47wt%Ti on magnetron sputtering conditions

Dependence of critical temperature and resistivity of thin film Nb47wt%Ti on magnetron sputtering conditions

Niobium-titanium multilayers generally have depressed critical temperature, T/sub c/. In this paper the variation of T/sub c/ and resistivity of magnetron sputtered Nb47wt%Ti thin films is studied as a function of the cathode power and target usage. The data are compared with analyses by Auger and scanning electron microscopy. Films made using a new target have properties which are similar to those of bulk Nb47wt%Ti when high cathode power is used. The data indicate a transition in the morphology of the film as power increases, which affects the rate at which interstitial atoms are incorporated into the growing film. After the target lost /spl sim/50% of its mass and acquired strong surface relief, bulk properties could not be obtained, because deposition rates for a given cathode power were lower than before. A small Ti enrichment (3-5%) between the films and the target was found for both sets of films.

D. Larbalestier | L. Cooley | C. D. Hawes

[1] N. Rizzo,et al. Pinning and vortex lattice structure in NbTi alloy multilayers , 1997, IEEE Transactions on Applied Superconductivity.

[2] R. Heussner,et al. Increased critical current density in Nb–Ti wires having Nb artificial pinning centers , 1997 .

[3] R. Somekh,et al. Origin of stresses in sputtered elemental and alloy thin films , 1996 .

[4] D. Larbalestier,et al. High critical current densities in Nb47%Ti multilayers with a planar copper flux pinning nanostructure , 1996 .

[5] Lee,et al. Flux-pinning mechanism of proximity-coupled planar defects in conventional superconductors: Evidence that magnetic pinning is the dominant pinning mechanism in niobium-titanium alloy. , 1996, Physical review. B, Condensed matter.

[6] Takahiro Matsumoto,et al. Blue‐green luminescence from porous silicon carbide , 1994 .

[7] J. Cuomo,et al. Compositional changes during magnetron sputtering of alloys , 1991 .

[8] D. W. Hoffman. Stress and property control in sputtered metal films without substrate bias , 1983 .

[9] W. Warnes,et al. Multilayer Nb-Ti for use as model superconducting microstructures , 1996 .

[10] D. W. Hoffman,et al. Internal stresses in sputtered chromium , 1977 .

[11] D. W. Hoffman,et al. Internal stresses in titanium, nickel, molybdenum, and tantalum films deposited by cylindrical magnetron sputtering , 1977 .