Oxide films are made by Pulsed Laser Deposition, a versatile physical vapor deposition technique commonly employed for the fabrication of complex oxide thin films. The general principle of PLD is quite simple: a high-power pulsed laser beam (usually an excimer laser) is focused to a pellet (target) of the desired material located in a vacuum chamber. The laser beam evaporates ions, neutral atoms and species from the target in what is said “the ablation-plume”. In front of the target, at about 50 mm, is located a substrate where a film made of the elements and stoichiometry contained the target itself starts to grow. Composition of the target material is usually that of the wanted phase, but off-stoichiometric targets are sometimes prepared to compensate for evaporation of high volatility elements or resputtering from the film surface. The typical film grow rates are in the 0.01 nm/laser pulse range, about 100 nm/hour for a 3Hz pulse repetition rate. Good film crystal quality is achieved by tuning the different growth parameters. For example the substrate temperature, which is typically of few hundreds of degrees Celsius, the oxygen pressure in the chamber (for oxides growth), usually between 1 mbar and 10-6 mbar, the intensity of the laser, that can reach several hundreds of milliJoules per pulse, equivalent to few MW of power (the laser pulse duration is about 20 ns). Target-to-substrate temperature is also an important parameter to consider when depositing films by PLD.

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EU This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N.828784.
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