Characterization of pulsed laser deposition plasmas using fast-framing photography and emission spectroscopy

摘要

Fast-framing photography and optical emission spectroscopy were used to study the expansion of a Pulsed Laser Deposition plasma obtained by irradiating a YBa2CU3O7-(x),, high-temperature superconducting target using an excimer laser. The effects of primary deposition parameters such as laser energy density, gas nature and pressure are presented, and plasma expansion models are used to give phenomenological explanations for Pulsed Laser Deposition plasma behavior. The effect of a polarized electrode placed in the plasma is also assessed. The presence of the electrode can, under certain conditions, preferentially excite oxides over elementary neutrals and ions; this is important in practical deposition conditions, since the presence of oxides is essential for producing high-quality high-temperature superconducting films.