In this invited lecture presented at conference ACMM22-Perth/2012 I reported on the details of advanced, improved electron-probe microanalysis with wavelength-dispersive spectroscopy WDS that was applied for quantitative analysis of chemical composition of Ce-doped BaTiO3. The emphasis was on original solutions/methods for the evaluation of inherent peak-overlap problem between the Ce-La1 and Ba-Lb1,4 that is present even when using the WDS. Using proposed peak-overlap correction methods and correct experimental WDS set-up I was able to achieve reliable and accurate quantitative results with ultimate experimental uncertainty of ( 1 % relative. Precise and accurate quantitative WDS results allowed me to accurately determine the solid solubility of Ce in the BaTiO3, to describe the perovskite solid solution formula and indirectly to define the mode of incorporation of Ce and the charge compensation mechanism of the dopant as well.
B.04 Guest lecture
COBISS.SI-ID: 25593639In this work the electrodeposition synthesis of nanowires based on magnetic Fe-Pd alloy with chemical composition close to the equiatomic ratio Fe/Pd ≈ 1 was described. By variation of the amount of FeCl3 electrolyte component the optimum conditions for co-deposition of the Fe and Pd were determined in order to obtain nanowires with stoichiometry ≈ Fe50Pd50. The morphology and elemental composition of the nanowires were analyzed using FEGSEM and EDS spectroscopic measurements. FEGSEM-BSE images revealed that the nanowires are 2-4 um long with a diameter of 0.2 um. Elemental analyses were performed using optimized low-voltage EDS-SDD set-up at 6.5 keV for spectroscopic measurements of the Fe-L and Pd-L X-rays and with spatial analytical resolution of 0.15 um. Consequently, we were able to determine accurate chemical composition of the nanowires on submicrometer scale. After annealing at 600 oC/1h the composition of synthesized Fe-Pd nanowires was uniform along the wires with stoichiometry between Fe40Pd60 and Fe50Pd50. Magnetic measurements showed that the coercivity up to 118 kA/m was achieved, which is the highest value reported for equiatomic Fe-Pd nanowires synthesized with the electrodeposition method.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 25798951In this contribution we have described the characterization of powders with anatase/titanium oxide nanoparticles (product of Cinkarna Celje) using the methods of high-resolution FEGSEM scanning electron microscopy. The samples were prepared by ultrasonic dispersion onto a polished Al-substrate, without additional coating and using coatings with amorphous carbon and/or Au-Pd alloy. Various experimental set-ups were applied for the analyses using two FEG-microscopes: JEOL JSM 7600F in JSI Ljubljana and Zeiss Sigma VP in Cinkarna Celje. The samples were investigated by “in-lens” SEM and transmission STEM imaging modes. From the obtained high-magnification electron micrographs (300.000 x) we found that the powders are composed of 30-50 nm sized agglomerates with the basic TiO2 nanoparticles ranged from 5 nm to 10 nm. The TiO2 nanoparticles were visible at the best on the images that were recorded on uncoated specimens using optimized FEGSEM set-up.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 26193447