|
Hasan AKYILDIZ |
Room/Lab: D-207 |
(+90)312 210 5919 |
E-mail: akhasan@metu.edu.tr |
|
|
Courses/Labs: |
Engineering Materials,
Materials Laboratory / Materials Characterization (XRD), Metallography |
Interests: |
Thin Film Production,
Hydrogen Storage, Powder Metallurgy |
|
Former Degree: B.S.; Ceramic Engineering
Dept, Anadolu University |
Current Degree: Ph.D.; Metallurgical and Materials Engineering Dept, METU |
|
Hydrogen Storage in Mg-Based Thin Films |
Supervisor: Dr. Tayfur ÖZTÜRK & Dr. Macit ÖZENBAŞ |
|
Thin
film processing is a versatile method which allows freer control on the
chemistry of materials. The method is therefore particularly suitable for
hydrogen storage alloys where the chemical control is essential to develop
hydrides with reduced stability. The current work aims to develop Mg based
hydrogen storage alloys of reduced stability, i.e.; the alloys that could
absorb and desorp hydrogen at temperatures less than 100˚C. Work is
currently in progress; to produce Mg based binary or multi-component thin
films both in amorphous and crystalline form; these for the purpose of identifying factors influential in metal-hydrogen interaction. |
|
Thermal evaporation is an easy method for the production of metallic
thin films. Photograph above shows a home-made thermal evaporation
system which allows a vacuum level as low as 10-6 mbar. The
unit has two evaporation sources, which can be increased to a maximum of
four when needed. This allows then co-deposition of 4 elements
simultaneously. The unit is used for the synthesis of Mg based hydrogen
storage alloys. |
|
mp |
|
mate |
|
Thin films when suitably engineered provides improved hydrogenation
properties. The structure shown above refer to such a film, i.e. Mg-Cu
film capped with Pd. The film can absorb hydrogen at RT within 3-5
min,(right). The stored hydrogen can be released at temperatures not
higher than 150ºC. For more details about hydrogen storage in thin films
see; H. Akyıldız, M. Ozenbas and T. Ozturk, Int J Hydrogen Energy (in
press), and H. Akyıldız, M. Ozenbas and T. Ozturk, J. Nanosci. Nanotechnol.,will
be submitted) |
|
|
|
Metallic thin films of suitable composition when reacted with hydrogen may alter their optical properties. Photograph above refers to Mg-Cu-Ni/Pd thin films. In the as-deposited state (left), the film is a opaque/mirror, but upon hydrogenation the film becomes transparent. This change in optical properties may be usefully employed in
thermochromic windows or with the measurement of transmittance or
reflectance, it can simply be used to follow the kinetics of hydrogen
sorption. |
|
fm |
|
