I just learned to know that I am listed with the Top 10,000 Scientists in Latin America and our university (UFRPE) got the 61st position in Latin America. Some of my scores in this ranking:
- 15th at UFRPE - 6022nd in Brazil - 7720th in South America & - 177777th in World. Ref: World Scientist and University Rankings 2021 - AD Scientific Index 2021
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am very happy to announce that my first master degree student, Francisco Torquato, has sucessfully defended his dissertation on last Friday, 9th of July, 2021. He is a very young and motivated researcher whom I am extremly proud of, and I am pretty sure that he will reach his next goals by his hardworking and inteligence.
The dissertation's title is "Glasses and Glass-Ceramics doped and co-doped with Yb3+, Er3+ and Nd3+ for optical thermometry". The results of this project have been already published as two scientific articles in the internationally recognized journals, while one invited chapter book and one more paper are in the process of writing at the moment of writing this post. We are thankful to Prof. Dr. Andrea de Camargo (IFSC-USP) and Prof. Albert Ocas (UACSA-UFRPE) for their worthy contribuition as the examination board, and to FACEPE for the granted scholarship. Well, first of all, I would like to congrats my students, Leonardo, Itamar and Francisco to participate in finalizing this work. It has been a time that I wanted to study this sort of materials and of course without working in a group it was hardly possible.
The paper is a young tentative research paper and we are looking for further research to answer the left questions. Interesteds could find this paper here. Photo adapted from here.
There is a lot on my wishlist for this year. But the most important one is everyone got a shot of the covid-19 vaccine. I hope this year brings a lot of hope and health, research and motivations for our community. This is to congrat our student, Francisco Alisson Torquato, for his fabulous hardworking and this recent publication. The article entitled "Influence of PbF2 content on optical thermometry of Er3+/Yb3+ co-doped tungsten sodium phosphate glasses" is published in journal of Optical Materials.
Abstract The green emissions of the trivalent erbium ions exhibit promising applications in photonics, such as the development of solid-state lasers, optical sensors, and light-emitting diodes (LED). In this work, the intensity of the emissions of two thermally coupled levels 2H11/2 and 4S3/2 excited states of Er3+ ions are studied in Er3+/Yb3+ co-doped tungsten sodium phosphate oxyfluoride glasses. The results demonstrate that an increase in the content of the PbF2 leads to an enhancement in the performance of these samples as optical sensors, and amplifies the relative thermal sensitivity from 0.82% K−1 to 1.15% K−1 for glass samples containing 10 mol% and 50 mol% of PbF2, respectively. Additionally, the effect of PbF2 is discussed in terms of the modifications of the site symmetries around Er3+ ions and changes in the energy gap between the thermally coupled levels, which implied in the improvement of the absolute thermal sensitivity at higher temperatures for high PbF2 contained sample. You may find this paper on this link.
This is one more publications thanks to our national and international collaborations. Spectral studies of highly Dy3+ doped PbO-ZnO-B2O3-P2O5 glassesAbstractPhosphate glasses having composition 50P2O5-10B2O3-20ZnO-20PbO–xDy2O3 where x = 0.04, 0.18, 0.36, 1.10, 1.80, and 3.60 mol% were prepared by melt quenching technique. The FTIR spectra reveal the different structural groups of the phosphate glass induced by modifiers such as lead oxide and zinc oxide, which could be explained in terms of the distortion of PO4 tetrahedra and network depolymerization process. The photoluminescence spectrum shows three prominent emission bands centered at 475, 586, and 675 nm corresponds to the 4F9/2 → 6HJ (J = 11/2, 13/2, 15/2) transitions, respectively, and the intensity ratio of yellow to blue emissions are enhanced as the concentration of Dy3+ ions increased up to 3.60 mol%. The 4F9/2 excited state's lifetime decreases by continuously increasing the amount of the trivalent lanthanide ion due to probable energy transfer between neighboring ions. The chromaticity diagram is studied as the rare-earth ion concentration, which gives the nearest condition to the white color at 0.36 mol% of the Dy3+ ions. |
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July 2021
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