Aleksejs Zolotarjovs, Krisjanis Smits, Anete Krumina, DonatsMillers, and Larisa Grigorjeva
Results show the possibilities of pore filling approach to modify alumina coatings with various materials in order to enhance coating optical (or other) properties and develop new functional materials; as well as demonstrate novel alumina phase transition detection approach. Luminescent PEO coatings were
produced on aluminum surface using pore-filling method. Three stage process was developed to modify alumina coating in order to enhance its luminescent properties. Eu3+ recharging to Eu2+ followed by significant (up to 10 times) total luminescence intensity increase was observed, Eu ion presence evaluated in final coating by measuring fast decay kinetics. Structure of obtained coatings was analyzed using XRD and FTIR spectroscopy indicating presence of η-alumina phase.
ECS Journal of Solid State Science and Technology, 5 (9) R150-R153 (2016)
L. Grigorjeva, D. Millers, K. Smits, A. Zolotarjovs
The ZnO coatings on Zn substrate were obtained using plasma electrolytic oxidation method. The XRDand SEM methods were used for structural and morphological characterization of obtained coatings. Theluminescence of ZnO coatings were studied and compared with luminescence characteristics of ZnO sin-gle crystal. It is shown that luminescence intensity in ZnO defect band depends on oxygen concentrationin ambient atmosphere. The effect is of interest for oxygen sensing based on ZnO coating luminescence
Sensors and Actuators A 234 (2015) 290–293
Krisjanis Smitsa, Donats Millers, Aleksejs Zolotarjovs,Reinis Drunka, Martins Vanks
Eu ion luminescence in aluminium oxide nanocrystals and layers prepared by plasma electrolytic oxida-tion (PEO) are investigated in this study. The Eu ion in PEO coatings has intense luminescence allowingsuch material to be used for preparation of various phosphor materials. In this study, Eu ion doped coatingswere prepared with two methods: anodization and pulsed bipolar plasma electrolytic oxidation. Also,for comparative studies, alumina nanocrystals with the same amount of Eu ions were prepared using SolGel and molten salts methods.Obtained Eu-doped coatings were studied using luminescence methods. Typical Eu ion luminescencebands were observed, however intensity and spectral distribution differs drastically depending on prepa-ration method and parameters used, therefore the Eu ion luminescence could be used as coating qualityluminescent probe. Additionally, the possibility to incorporate the Eu ions in trivalent or divalent stateexhibiting bright red and blue luminescence accordingly was demonstrated by using different oxidationparameters. Moreover, comparison measurements between powder samples and coatings were made.
Applied Surface Science 337 (2015) 166–171