Plasma assisted in situ laser deposition of Y 1Ba 2Cu 3O 7−x superconducting thin films with laser heating and annealing

Abstract

Single-chamber laser processing of high temperature Y 1Ba 2Cu 3O 7−x thin films on SrTiO 3 (100), ZrO 2(100) and MgO(100) substrates was carried out using plasma assisted in situ laser deposition. The films were deposited by XeCl excimer laser ablation at substrate temperatures as low as 450–550°C. A dc oxygen plasma at a partial pressure of up to 200 mtorr forced oxygen incorporation during the film growth at a low substrate temperature. The problem of firing and maintaining the discharge was solved by appropriate electrode geometry. Direct cw CO 2 laser irradiation of the substrate surface and excimer laser plume were used to reduce the density of particulates. The films were characterized by: X-ray diffraction, four-point probe ac electrical resistivity measurements, SEM and XMA. A T c onset of ∼88–90 K and J c ∼ 7 × 10 5 A cm −2 at 4.2 K were measured.