KrF pulsed laser deposition of chromium oxide thin films from Cr8O21 targets

摘要

Chromium oxides, CrxOy, are of great interest due to the wide variety oftheir technological applications. Among them, CrO2 has been extensivelyinvestigated in recent years because it is an attractive compound to be used inspintronic heterostructures. However, its synthesis at low temperatures hasbeen a difficult task due to the metastable nature of this oxide. This isindeed essential to ensure interface quality and the ability to coatthermal-sensitive materials such as those envisaged in spintronic devices.Pulsed Laser Deposition (PLD) is a technique that has the potential to meet therequirements stated above. In this work, we describe our efforts to growchromium oxide thin films by PLD from Cr8O21 targets, using a KrF excimerlaser. The as-deposited films were investigated by X-ray diffraction andRutherford backscattering spectrometry. Structural and chemical compositionstudies showed that the films consist of a mixture of amorphous chromium oxidesexhibiting different stoichiometries depending on the processing parameters,where nanocrystals of mainly Cr2O3 are dispersed. The analyses do not excludethe possibility of co-deposition of Cr2O3 and a low fraction of CrO2. PACS: 81.15.Fg, 75.50.Dd