Pulsed Laser Deposition

Producing thin films via Pulsed Laser Deposition is a very versatile thin film deposition technique that is used at the IFW Dresden for the preparation of a number of functional thin film systems. A pulsed high-energy laser beam (preferably UV-light with about 30 ns pulse length) is focused on a target material. A surface-near area is heated up very rapidly, melts and evaporates (ablation process). Due to further interaction of the ablated material with the laser radiation a plasma, the socalled laser plume, is formed. The laser plume propagates in a direction normal to the target surface and reaches the substrate where a thin film is deposited. The main advantages of this method are the stoichiometric material transfer from target to substrate, the simplicity and flexibility of the process which also allows a film deposition under UHV conditions as well as at high pressures (several mbar) in reactive atmosphere and last but not least the relatively simple growth of complex multi-layer structures.

At the Institute for Metallic Materials, we use this technique preferably for oxides like high Tc or magnetic thin films and intermetallic systems like superconductors or hard magnetic thin films. In the area of high Tc films we work on the deposition of buffer layers and doped and undoped REBaCuO films and multilayers, which are of special interest for Y123 coated conductor. Ion-beam-assisted PLD is used to deposit highly biaxially textured oxide films on amorphous substrates that are then used as templates for the further growth of highly oriented functional thin films. Also superconducting intermetallic compounds (e.g. RENiBC) and heterostructures attracted our interest due to interesting interaction effects of superconductivity and magnetism. A very important second working area is the deposition of magnetic thin films. We focus on the UHV pulsed laser deposition of hardmagnetic NdFeB, SmCo and FePt thin films and on the deposition and characterization of manganate thin films and multilayers that show the colossal magnetoresistive (CMR) effect and are of high interest for oxide electronics. Finally, we started to work on oxide superlattices to study the influence of the interfaces on the functional properties of materials and to prepare films of the newly discovered pnictide superconductors.

For the preparation of high quality thin films by Pulsed Laser Deposition, it is essential to know more about the physics involved in the PLD-process. Therefore, we also perform laser plume diagnostics besides the actual thin film deposition.