Moldavian Journal of the Physical Sciences (Apr 2008)

Influence of strong disorder on superconductivity of MgB2 thin films

  • Koch, Thomas,
  • Zdravkov, I.,
  • Surdu, Andrei,
  • Condrea, Elena,
  • Socrovişciuc, Alexei,
  • Sidorenko, Anatolie,
  • Rossolenko, A,
  • Ryazanov, V,
  • Straumal, B,
  • Tidecks, Reinhard,
  • Wixforth, Achim

Journal volume & issue
Vol. 7, no. 2
pp. 164 – 167

Abstract

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We investigated the influence of disorder on superconductivity of MgB2 films, prepared in a single deposition run onto two different substrates: (100)-MgO and on (128° rot)-LiNbO3 with trigonal crystal structure which does not match to the MgB2 structure. As expected, the microstructure of both films crucially differs. The REM study shows a very homogeneous, smooth morphology of the MgB2 film on MgO, but a very rough inhomogeneous film structure on LiNbO3. Although the MgB2 film on LiNbO3 is strongly disordered, its critical temperature Tc=33.5 K is practically the same as for the film deposited on MgO. Possible reasons of such unusual Tc behavior are discussed.