Dynamical plasma study during CaCu3Ti4O12 and Ba0.6Sr0.4TiO3 pulsed laser deposition by local thermodynamic equilibrium modelling

• Published in: Journal of physics. D, Applied physics Applied physics, 2010-07, Vol.43 (28), p.285202-285202
• Main Authors: Lagrange, J F, Hermann, J, Wolfman, J, Motret, O
• Format: Article
• Language: English
• Subjects: CERAMICS; Condensed matter: electronic structure, electrical, magnetic, and optical properties; COPPER OXIDE; Cross-disciplinary physics: materials science; rheology; DEPOSITION; Dielectric thin films; Dielectrics, piezoelectrics, and ferroelectrics and their properties; EQUILIBRIUM; Exact sciences and technology; Excimer lasers; IRRADIATION; Laser deposition; LASERS; Local thermodynamic equilibrium; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; MICA; Optics; Physics; Plasma diagnostics; Plasma temperature; PLASMAS; Pulsed laser deposition; Radiance; Resonance lines; THERMODYNAMIC PROPERTIES; THIN FILMS
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/43/28/285202

We performed space- and time-resolved plasma diagnostics during pulsed laser deposition of CaCu3Ti4O12 (CCTO) and Ba0.6Sr0.4TiO3 (BSTO) thin films. A KrF excimer laser irradiation at 248 nm with 25 ns pulse duration irradiates targets with a fluence varying from 1 to 2 J cm-2 under an oxygen pressure varying from 5 to 30 Pa. The plasma is shown to be optically thick and strongly non-uniform during the early expansion stage and the resonance lines Ca II 393 and 396 nm are strongly self-reversed during this time. Plasma temperature, electron density and relative elemental concentrations were obtained by comparing the experimental emission spectra with the spectral radiance computed for a non-uniform plasma in local thermal equilibrium. In this way, it was possible to evaluate very low concentrations of pollutants present in irradiated samples.