The formation and characterization of Tl doped Hg-Ba-Ca-Cu-O superconducting films synthesised through spray pyrolysis

Abstract

The Tl doped Hg-Ba-Ca-Cu-O HTSC films have been synthesised by reacting Ba-Ca-Cu-O precursor films deposited by spray pyrolysis with a mixture of Hg-Tl vapour in an evacuated sealed quartz tube. These films (∼ 3 μm in thickness) having 1223 as the majority phase are found to possess Tc(R = 0)'s of 127 K and 122 K on MgO (100) and ZrO2 (100) single-crystal substrates, respectively, and Jc ∼ 105 A/cm2 (both MgO and ZrO2 have 20 K). The observed Tc(R = 0) of 127 K is the highest reported so far for Tl doped Hg-Ba-Ca-Cu-O films. Surface morphological investigations reveal the occurrence of layered spiral-like growth features.