D.Stanoi, G.Socol, C.Grigorescu, F.Guinneton, O.Monnereau, L.Tortet, T.Zhang, I.N.Mihailescu, Chromium oxides thin films prepared and coated in situ with gold by pulsed laser deposition, Materials Science & Engineering, B: Solid-State Materials for Advanced Technology B118/1-3 (2005) 74-78

Title: Chromium oxides thin films prepared and coated in situ with gold by pulsed laser deposition

Abstract: Chromium dioxide is a very suitable compound for spintronic devices. It is ferromagnetic at room temperature (T-c = 395 K) and has a half-metallic band structure. CrO2, has been theoretically predicted to be100% spin polarized at the Fermi level. For some applications in spintronics low deposition temperatures are required. However, the fabrication of single phase thin films of CrO2 at low temperature is quite difficult due to its metastable character. In this work we report our experiments to deposit thin films of chromium oxides by reactive pulsed laser deposition (RPLD). RPLD experiments were performed with a UV KrF* excimer laser source (t(FWHM) >= 20ns, lambda = 248 nm) in different conditions regarding the target, the substrate temperature, the atmosphere inside the deposition chamber and the laser fluence. In order to prevent the reduction of CrO2, to Cr2O3 in thin films preserved in ambient conditions some of the samples were capped with gold in situ using the same set-up. The composition and morphology of the deposited films were characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy. A higher and stable content of CrO2 in the deposited films was evidenced in the case of samples capped with Au. Subsequent analysis performed after 4 months showed no difference in the content of the film. (c) 2004 Elsevier B.V. All rights reserved.

Key words: reactive pulsed laser deposition; chromium dioxide; spintronic devices