Thursday, 8 August, 2013, 21:35 Posted by Zbigniew Starowicz
I would like to look closer the influence of film thickness and annealing temperature on the obtained microstructure (particles geometry) and optical properties. For that purpose I prepared poliched silicon wafers and microscope base glass. Those substrates were cut and cleaned with isopropanol and acetone. Next silicon wafers were passivated. Passivation is process of thermal surface oxidation realized in 850 Celsius degrees in oxygen atmosphere. After 15 minutes about 20nm thick layer of silicon dioxide occur at the surface and act as seperation layer between metal nanoparticles and semiconductor surface. Subsequently on those substrate silver film of thickness 11,14,17 and 20 nm was sputtered. Samples with each thickness was annealed at the 200, 300 and 400 Celsius degrees for 1 hour. For internal stress determinstion I try to apply XRD methods. Obtained samples will be examined with SEM and AFM for microstructure description. Optical properties investigation will include diffused and specular reflectance and transmission measurements
Thursday, 8 August, 2013, 16:08 Posted by Jakub Kawalko
Recently some of thin foils from KoBo extruded samples (comercial purity titanium and high purity zinc) have finally been examined in TEM and some crystal orientation microscopy have been performed on them. What was interesting is that although on SEM with EBSD, measured grain sizes are generally in micron range in TEM all types of deformed samples seems to have some nanostructures in them. This is especially visible in case of zinc where we could see 100 nm diameter grains in TEM while on EBSD average grain size was in range of 20 micrometers. Observed nanostructures can be responsible for characteristic fluctuation of misorientations inside zinc grains. Second interesting observation is that although diffraction patterns from zinc seem to be of good quality, indexing program is unable to properly solve diffraction for zinc lattice. Our colleagues from AGH already had similar problems but in case of SAD patterns. It seems as though zinc after KoBo had different lattice parameters than the same material before the deformation.
PhD report (July 2013) K. Stan
Wednesday, 7 August, 2013, 16:49 Posted by Katarzyna Stan
Main studies carried out during this month: - TEM investigations on the samples with Ti, Zr and Hf addition after annealing - participation in the conference The 20th International Symposium on Metastable, Amorphous and Nanostructured Materials (ISMANAM 2013). During poster session I presented work with the title: „“Effect of Ti, Zr and Hf addition on microstructure and properties of rapidly solidified Al-Mn-Fe alloy”.
Wednesday, 31 July, 2013, 19:21 Posted by Honorata Kazimierczak
In July I’ve worked on my next publication, entitled :” Tin-zinc alloy electrodeposition from citrate baths”. In this paper I described in details the results obtained during the firsth and the second year of my studies, when I was studying ternary system Sn(II)-Zn(II)-Mo(VI). Currently I resigned from putting this part concerning Sn deposition in my doctoral thesis, because the system Zn(II)-Mo(VI) is the most interesting and difficult enough to write a doctoral dissertation about it. But, in my opinion the results concerning the tin-zinc alloy deposition are worth to be published.
Tuesday, 30 July, 2013, 10:35 Posted by Zbigniew Starowicz
This experiment was based on colloidal coere-shell particles with empty core and small ( 8-9nm) silver particles adsorbed on particle surface. After deposition of particles using LbL method sample was illuminated by Xenon lamp radiation for 30 min with irradiation power density of 50 mW/cm^2. Small silever particles should warm up after illumination due to the localized surface plasmon resonance and burn polyelectrolyte shell. Bigger particles schould be build. Detection of this reaction should be visible as the shift of the LSPR wavelength. Unforunathely this has been not observed yet.
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