STARK-BROADENING DIAGNOSTICS OF THE ELECTRON-DENSITY IN THE LASER-ABLATION PLUME OF YBA2CU3O7-X AND PBZRXTI1-XO3

Diagnostics of pulsed laser ablation and deposition of superconductive YBCO (YBa2Cu3O7-x) and ferroelectric PZT (PbZr xTi1-xO3) thin films has been accomplished by measuring the Stark broadening of the laser produced plume. Fluorescence emission has been collected from regions along the axis of the plume at different distances from the target surface. The line shape of some selected transitions has been analyzed and the electron density ne determined from the observed linewidth. The measured values of ne are in the range 0.4-30×1017 cm-3 for YBCO and 0.1-6×1017 cm-3 for PZT. A scaling law of n e as a function of the distance from the target has been found, which indicates a one-dimensional behavior in the early stage of the electron cloud expansion. The dependence of ne on the presence of the ambient oxygen gas and on the laser fluence has been also investigated. The results of the diagnostics are compared with theoretical predictions and correlated with the deposition parameters. © 1994 American Institute of Physics.