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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:50 |
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Conference: Bucharest University Faculty of Physics 2016 Meeting
Section: Optics, Spectroscopy, Plasma and Lasers
Title:
W, mg and c composite thin films deposited by pulsed laser deposition
Authors:
L.N. DUMITRESCU 1,2, V.ION 1, A.MOLDOVAN 1, A. BERCEA 1,3, D. COLCEAG 1, Maria DINESCU 1
Affiliation:
1 National Institute for Laser, Plasma and Radiation Physics, Atomistilor 409, PO-Box MG-16, 077125, Magurele, Bucharest, Romania
2 University of Craiova, Faculty of Sciences, Craiova, Romania
3 University of Bucharest, Faculty of Physics, Bucharest, Romania
E-mail
nicoleta.dumitrescu@inflpr.ro, ln_dumitrescu@yahoo.com
Keywords:
carbon, tungsten , PLD, composite
Abstract:
Different studies were performed regarding the properties of ternary systems based on tungsten, beryllium, and carbon which include nitrogen(N2) and hidrogen(H2) as inevitable intrinsic impuritys. The topic represents an important aspect for ITER facility, where such compound are formed in different parts of the tokamak machine. The experiments are difficult because Be toxicity: it is replaced by Mg, which has similar properties. We report in this work on the deposition and characterization of thin films containing C, W and Mg in chemical compounds including N2 and H2 .
The layers were grown by Pulsed Laser Deposition (PLD). A Nd:YAG pulsed laser (wavelength of 1064 nm, pulse energy of 16-60 mJ and pulse width of 6 ns) has been used to alternatively ablate tungsten, magnesium and graphite solid targets (W/Mg/C) using a rotation-translation system with three different targets holders. Si plates were used as substrates, at temperatures between 200 °C and 600°C. The composition of the gas mixture (Ar, H2, N2), the number of pulses and the substrate temperature were varied in order to find the optimal growth conditions.
The deposited layers were investigated morphologically, structurally, compositional and optical by atomic force microscopy (AFM), X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS) and spectroellipsometry (SE) respectively. We obtained W/Mg/C composite thin films with low roughness values (in the nanometers range) and thicknesses between 20 and 150 nm.
Acknowledgement:
EURATOM, Consortiu EUROFUSION 1EU-12/01.01.2016 (WPEDU-RO).
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