Epitaxial HgBa2Ca2Cu3O<i>y</i> films on SrTiO3 substrates prepared by spray pyrolysis technique

Abstract

HgBa2Ca2Cu3Oy (Hg-1223) films with a thickness of 1–2 μm and Tc (zero)∼130 K have been fabricated by utilizing a spray pyrolysis technique. X-ray diffraction indicates that the films consist of predominantly Hg-1223 phase grains with c-axis orientation. Moreover, the oscillation photograph taken by a Weissenberg camera confirms that the film grains are in-plane aligned and epitaxially grown on SrTiO3. In electrical transport measurements, the as-fabricated film exhibits a Tc (zero) of 123 K, and a zero-field Jc of 3.7×105 A/cm2 at 77 K. Additional post-annealing at 320 °C for 50 h in flowing oxygen has improved the transport properties as Tc (zero)∼130 K and Jc∼4.4×105 A/cm2 (77 K, 0 T).