Preparation of epitaxial TlBa2Ca2Cu3O9 high T c thin films on LaAlO3 (100) substrates

Abstract

Epitaxial TlBa2Ca2Cu3O9 high Tc thin films were prepared on LaAlO3 (100) substrates by a combination of laser ablation and thermal evaporation of thallium oxide. X-ray diffraction patterns of θ-2θ scans showed that the films consisted of highly c axis oriented TlBa2Ca2Cu3O9. φ scan measurements revealed an epitaxial growth of the TlBa2Ca2Cu3O9 thin films on the LaAlO3 (100) substrates. Ac inductive measurements indicated the onset of superconductivity at 110 K. At 6 K, the critical current density was 4×106 A/cm2 in zero magnetic field and 6×105 A/cm2 at a magnetic field of 3 T parallel to the c axis.

In situ preparation of epitaxial TlBa2Ca2Cu3O9 high-T c thin films

“…3 ͑a͔͒, with a thallium-free BaCaCuO precursor film deposited by laser ablation and postannealed in an O 2 /Tl 2 O atmosphere. 5,7 The film showed plates ͑diameter typically 50 m͒ and holes. A Tl-1223 film deposited by the in situ method ͓Fig.…”

“…In a first step a polycrystalline ͑Tl͒BaCaCuO precursor film, either thallium free or containing thallium, was deposited by several methods such as sputtering, 2 laser ablation, [3][4][5] or spray pyrolysis. 6 In a second step thallium was introduced into the precursor film by a heat treatment in the presence of O 2 and Tl 2 O vapor for forming of the Tl-1223 phase.…”