Hydrogen absorption in magnesium based crystalline thin films

Akyildiz, Hasan
Ozenbas, Macit
Öztürk, Tayfur
A study is carried out for hydrogenation of Mg based thin films produced via thermal evaporation. Films produced were pure Mg, Mg capped with Au-Pd, Mg-Cu co-deposited and Mg-Cu multilayered. The films under the experimental conditions employed were crystalline with columnar grains with some degree of preferred orientation. In multi-component systems, the films in the as-deposited state were made of individual elements, but upon hydrogenation at temperatures greater than 473K, the elements react with each other yielding the intermetallic phases. The study showed that, of the systems studied in this work, Mg-Cu multilayer yielded the most favorable result as useful storage system, for Mg portion of the film can be converted totally into MgH2, this occurring at temperatures not greater than 473 K. The study implies that if the as-deposited structure were to be used and preserved as hydrogen storage medium, there is a narrow temperature window for hydrogenation. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.


Hydrogen storage in magnesium based thin films
Akyıldız, Hasan; Öztürk, Tayfur; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2010)
A study was carried out for the production of Mg-based thin films which can absorb and desorb hydrogen near ambient conditions, with fast kinetics. For this purpose, two deposition units were constructed; one high vacuum (HV) and the other ultra high vacuum (UHV) deposition system. The HV system was based on a pyrex bell jar and had two independent evaporation sources. The unit was used to deposit films of Mg, Mg capped with Pd and Au-Pd as well as Mg-Cu both in co-deposited and multilayered form within a t...
Thickness effects in hydrogen sorption of Mg/Pd thin films
Gharavi, Ayshe G.; Akyildiz, Hasan; Öztürk, Tayfur (2013-12-15)
Mg thin films with various thicknesses ranging from 50 to 1000 nm capped with Pd have been prepared by thermal evaporation and their hydrogen sorption properties were examined following the electrical resistance change. The study showed that the hydrogenation and dehydrogenation temperatures correlate with the film thickness, thinner films reacting with hydrogen at reduced temperatures. It is concluded that films thinner than 200 nm react fully with hydrogen, while a considerable portion of the thicker film...
Hydrogen sorption in crystalline and amorphous Mg-Cu thin films
Akyildiz, Hasan; Öztürk, Tayfur (2010-03-04)
A study was carried out to examine the hydrogenation behavior of 300 nm, Pd-capped, Mg-Cu thin films with Cu contents of 5, 10 and 15 at.%. The films were produced via thermal evaporation of Mg and Cu co-deposited onto glass substrates at two different temperatures: 298 and 223 K. The samples produced at 298 K were all crystalline, the structure being refined with increase in the Cu content. The films deposited at 223 K developed structures that were either refined, i.e. Mg(95)Cu(5); or amorphous, i.e. Mg(9...
Structural characteristics of thermally evaporated Cu0.5Ag0.5InSe2 thin films
Gullu, H. H.; Parlak, Mehmet (2016-05-01)
In this work, Cu0.5Ag0.5InSe2 (CAIS) thin film samples were prepared by thermal evaporation of Cu, Ag, InSe and Se evaporants sequentially on glass substrates. Following the deposition, annealing processes were applied at different temperatures. The as-grown and annealed CAIS samples were nearly stoichiometric in the detection limit of the compositional measurement. The x-ray diffraction (XRD) measurements revealed that they were in polycrystalline structure with a preferred orientation along the (112) dire...
Deposition of CZTSe thin films and illumination effects on the device properties of Ag/n-Si/p-CZTSe/In heterostructure
Bayrakli, O.; Terlemezoğlu, Makbule; GULLU, H. H.; Parlak, Mehmet (2017-06-30)
Characterization of Cu2ZnSnSe4 (CZTSe) thin films deposited by thermal evaporation sequentially from the pure elemental sources and in-situ post annealing was carried out at 400 C under Se evaporation atmosphere. Another annealing process was applied in nitrogen atmosphere at 450 degrees C to get poly-crystalline monophase CZTSe film structure. XRD analysis together with Raman spectroscopy was used to determine the structural properties. Spectral optical absorption coefficient evaluated from transmission da...
Citation Formats
H. Akyildiz, M. Ozenbas, and T. Öztürk, “Hydrogen absorption in magnesium based crystalline thin films,” INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, pp. 1379–1383, 2006, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31783.