|VĚDA|SCIENCE|

@article{Hrabovsky_MOTZB_2024,

title = {Optical, magneto-optical properties and fiber-drawing ability of tellurite glasses in the TeO2–ZnO–BaO ternary system},

author = {J. Hrabovsky, L. Strizik, F. Desevedavy, S. Tazlaru, M. Kucera, L. Nowak, R. Krystufek, J. Mistrik, V. Dedic, V. Kopecky, G. Gadret, T. Wagner, F. Smektala, M. Veis},

url = {https://doi.org/10.1016/j.jnoncrysol.2023.122712},

doi = {10.1016/j.jnoncrysol.2023.122712},

issn = {1873-4812},

year  = {2024},

date = {2024-01-15},

journal = {Journal of Non-Crystalline Solids},

volume = {624},

number = {122712},

abstract = {The presented work is focused on the optical and magneto-optical characterization of TeO2-ZnO-BaO (TZB) tellurite glasses. We investigated the refractive index and extinction coefficient dispersion by spectroscopic ellipsometry from ultraviolet, λ ≈ 0.193 μm, up to mid-infrared, λ ≈ 25 μm spectral region. Studied glasses exhibited large values of linear (n632 ≈ 1.91–2.09) and non-linear refractive index (n2 ≈ 1.20–2.67×10−11 esu), Verdet constant (V632 ≈ 22–33 radT−1m−1) and optical band gap energy (Eg ≈ 3.7–4.1 eV). The materials characterization revealed that BaO substitution by ZnO leads (at constant content of TeO2) to an increase in linear and nonlinear refractive index as well as Verdet constant while the optical band gap energy decreases. Fiber drawing ability of TeO2–ZnO–BaO glassy system has been demonstrated on 60TeO2–20ZnO–20BaO glass with presented mid-infrared attenuation coefficient. Specific parameters such as dispersion and single oscillator energy, Abbe number, and first-/third-order optical susceptibility are enclosed together with the values of magneto-optic anomaly derived from the calculation of measured dispersion of the refractive index.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bulgakov_BiCol_2024,

title = {Dual-wavelength femtosecond laser-induced single-shot damage and ablation of silicon},

author = {Alexander V. Bulgakov, Juraj Sládek, Jan Hrabovský, Inam Mirza, Wladimir Marine, Nadezhda M. Bulgakova},

url = {https://doi.org/10.1016/j.apsusc.2023.158626},

doi = {10.1016/j.apsusc.2023.158626},

issn = {0169-4332},

year  = {2024},

date = {2024-01-15},

journal = {Applied Surface Science},

volume = {643},

number = {158626},

abstract = {An experimental and theoretical study of laser-induced damage and ablation of silicon by two individual femtosecond pulses of different wavelengths, 1030 and 515 nm, is performed to address the physical mechanisms of dual-wavelength ablation and reveal possibilities for increasing the ablation efficiency. The produced craters and damaged areas are analyzed as a function of laser fluence and time separation between the pulses and are compared with monochromatic irradiation. The order of pulses is demonstrated to be essential in bi-color ablation with higher material removal rates when a shorter-wavelength pulse arrives first at the surface. Simulations based on the two-temperature model show that the visible pulse is profitable for the generation of the electron-hole plasma while the delayed IR pulse is efficiently absorbed in the plasma enhancing energy coupling to the target. At long delays of 30–100 ps, the dual-wavelength ablation is found to be particularly strong with formation of deep smooth craters. This is explained by the expansion of a hot liquid layer produced by the first pulse with a drastic decrease in the surface reflectivity at this timescale. The results provide insight into the processes of dual-wavelength laser ablation offering a better control of the energy deposition into material.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{wang_2023,

title = {Magneto-Optical Spectroscopy of Epitaxial CoxFe3-xO4 (001) Thin Films},

author = {S. Wang, H. Onoda, J. Hrabovsky, H. Yanagihara, J. Inoue, M. Veis, T. Ishibashi},

url = {https://doi.org/10.3379/msjmag.2311R001},

doi = {10.3379/msjmag.2311R001},

issn = {1882-2932},

year  = {2023},

date = {2023-12-01},

urldate = {2023-12-01},

journal = {Journal of the Magnetics Society of Japan},

volume = {47},

issue = {6},

pages = {137-143},

abstract = {The magneto-optical (MO) spectra of spinel cobalt ferrite thin films with different distortions were measured in a broad range of 0.59 – 3.54 eV. Instead of using the cation substitution method, we prepared cobalt ferrite thin films with local distortion by using a RF magnetron sputtering method on an Mg2SnO4 buffer layer to induce epitaxial strain. We derived the diagonal and off-diagonal elements of the dielectric tensor to investigate the influence of distortion on the MO effect in the films. In the spectra of the off-diagonal dielectric elements, the transitions at 0.8, 1.8, and 2.0 eV, which correspond to the optical transitions of tetrahedral (Co2+) and octahedral [Co2+], [Fe3+], were assigned to crystal field (CF) transitions: (Co2+): 4A2 → 4T1(F), 4A2 → 4T1(P) and intervalence charge transfer (IVCT) transition: [Co2+]t2g → [Fe3+]t2g, respectively. This result revealed that the Co ions were present in both the tetrahedral and octahedral sites in the epitaxial CFO thin films. By comparing the relative amplitude of each MO transition of cobalt ferrite thin films with different distortions, we found that MO spectroscopy is a highly promising tool for evaluating local distortions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovsky_EPR_2023,

title = {Correlated EPR and optical study of charge trapping phenomena in tellurite glasses. The role of barium oxide},

author = {J. Hrabovský, M. Buryi, V. Babin, K. Ridzoňová, K. Paurová, D. John},

url = {https://doi.org/10.1016/j.jnoncrysol.2023.122596},

doi = {10.1016/j.jnoncrysol.2023.122596},

issn = {1873-4812},

year  = {2023},

date = {2023-08-21},

urldate = {2023-08-21},

journal = {Journal of Non-Crystalline Solids},

volume = {620},

number = {122596},

pages = {1-9},

abstract = {Tellurite glasses of the compositions TeO2(60%)-ZnO(40%) and TeO2(60%)-ZnO(20%)-BaO(20%) were prepared in the bulk form with following grinding into powders. The samples were X-ray irradiated. The created charge trapping centers were studied in both types of samples using electron paramagnetic resonance (EPR) spectroscopy. The O− defect and two types of F+ centers were discovered. One of the F+ center remained unchanged whereas the other one as well as the O− defect were affected by the presence of BaO. Moreover, photo-, radio- and thermoluminescence (PL, RL, TL, respectively) methods were applied as well. The discovered charge trapping centers have been proven to influence luminescence properties as well – improving them in the TeO2(60%)-ZnO(40%) and vice versa degrading them in the TeO2(60%)-ZnO(20%)-BaO(20%) glasses. The effect was even stronger in the grinded samples as compared to the bulk ones. The role of the BaO has been disclosed as supporting oxygen leakage from the host.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovsky_BDD_2023,

title = {Laser-patterned boron-doped diamond electrodes with precise control of sp2/sp3 carbon lateral distribution},

author = {J. Hrabovsky, M. Zelensky, J. Sladek, M. Zukerstein, J. Fischer, K. Schwarzova-Peckova, A. Taylor, M. Veis, S. Mandal, O.A. Williams, N.M. Bulgakova},

url = {https://doi.org/10.1016/j.apsusc.2023.158268},

doi = {10.1016/j.apsusc.2023.158268},

issn = {1873-5584},

year  = {2023},

date = {2023-08-14},

urldate = {2023-08-14},

journal = {Applied Surface Science},

volume = {639},

number = {158268},

abstract = {A thorough study on sp3 to sp2 carbon conversion in undoped and boron-doped diamond (BDD) thin (approx 500 nm) layers leading to the desired sp2/sp3 carbon ratio and lateral distribution, which utilises boron atom incorporation and infrared (IR) material laser processing has been performed. Polycrystalline as-grown (AG) or chem-mechanically polished (CMP) undoped diamond/BDD layers were investigated with respect to boron content and laser wavelength (800, 1030 nm). Boron incorporation leads to an increase in IR optical absorption and reduction of required energy fluence (Fth ~ 1 Jcm-2) needed for sp3 to sp2 carbon conversion. Raman spectroscopy was performed to identify carbon conversion stages and to tailor the ideal parameters for other IR laser sources and required sp2/sp3 carbon ratio. Electrochemical parameters (Delta Ep and Delta IAp/ICp ratio) were obtained from cyclic voltammetry measurements of outer-([Ru(NH3)6]3-/4-) and inner-([Fe(CN)6]3+/2+) sphere redox markers. Values of Delta Ep and IAp/ICp are mainly influenced after conversion of 10% of sp3 to sp2 carbon. This trend is most pronounced for the [Fe(CN)6]3-/4- redox marker, by decrease or increase of these parameters on AG or CMP BDD electrodes respectively. Electrochemical findings were supported by electrochemical impedance spectroscopy where Rct keeps the same trend as Delta Ep values and double layer capacitance profoundly increases between 10 and 25% of surface conversion.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hrabovsky2023,

title = {Picosecond pulsed laser deposition of MoS2 thin films},

author = {Jose Guadalupe Quionones-Galvan and Inam Mirza and Jan Hrabovsky and Enrique Campos-Gonzalez and Francisco De Moure-Flores and Jose Santos-Cruz and Miguel Angel Santana-Aranda and Alexander V. Bulgakov and Nadezhda M. Bulgakova},

url = {https://www.mmscience.eu/journal/issues/june-2023/articles/picosecond-pulsed-laser-deposition-of-mos2-thin-films},

doi = {10.17973/MMSJ.2023_06_2023003},

issn = {1805-0476},

year  = {2023},

date = {2023-06-01},

journal = {MM Science Journal},

volume = {June},

pages = {6421-6425},

abstract = {MoS2 thin films were grown by the pulsed laser deposition

technique using a picosecond laser at a wavelength of 1030 nm.

The plasma ion mean kinetic energy and density were estimated

from the time-of-flight distributions measured using a Langmuir

planar probe. It has been found that the mean kinetic energy

decreases with increasing the laser pulse energy. This unusual

effect is explained by the difference in the volatility of the

vaporized species. Samples were structurally characterized by

Raman spectroscopy and grazing angle X-ray diffraction. It was

found that thin films of amorphous matrices containing MoS2

nanocrystallites were grown. Optical characterization carried

out by UV-vis spectroscopy yielded transmittance values above

90% in the visible spectral range and an indirect electronic

transition at 1.4 eV. Chemical oxidation states for molybdenum

and sulfur were analyzed by means of X-ray photoelectron

emission spectroscopy, which revealed Mo-S bonding states,

confirming the growth of MoS2.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Taylor2023,

title = {Comparative determination of atomic boron and carrier concentration in highly boron doped nano-crystalline diamond},

author = {A. Taylor, P. Ashcheulov, P. Hubík, Z. Weiss,

L. Klimša, J. Kopeček, J. Hrabovsky, M. Veis,

J. Lorinčík, I. Elantyev, V. Mortet},

url = {https://doi.org/10.1016/j.diamond.2023.109837},

doi = {10.1016/j.diamond.2023.109837},

issn = {1879-0062},

year  = {2023},

date = {2023-03-11},

urldate = {2023-03-11},

journal = {Diamond and Related Materials},

number = {109837},

abstract = {We have compared the total boron content and hole carrier concentration values obtained from various destructive and non-destructive quantification methods in boron doped nano-crystalline diamond films prepared over a range of doping levels, using microwave plasma enhanced chemical vapour deposition. Destructive secondary-ion mass spectrometry and relatively unreported glow discharge optical emission spectrometry were complemented by non-destructive Raman, spectroscopic ellipsometry and van der Pauw Hall measurements. Measurement techniques are discussed, including details of the glow discharge optical emission spectrometry technique; use of different laser powers and wavelengths, fitting parameters for Raman spectroscopy, and improved ellipsometry modelling. Finally, measured values are compared and discussed regarding their viability for estimation of total boron and electrically active boron in doped nano-crystalline diamond layers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Zukerstein2022,

title = {Formation of tubular structures and microneedles on silicon surface by doughnut-shaped ultrashort laser pulses},

author = {M.Zukerstein, J.Hrabovsky, J.Sladek, I.Mirza, Y.Levy, N.M.Bulgakovaa},

url = {https://www.sciencedirect.com/science/article/pii/S0169433222007875},

doi = {https://doi.org/10.1016/j.apsusc.2022.153228},

issn = {0169-4332},

year  = {2022},

date = {2022-04-13},

journal = {Applied Surface Science},

volume = {592},

number = {153228},

abstract = {We report on the formation of tubular structures and microneedles on the surface of monocrystalline silicon using ultrashort laser pulses. Highly deterministic surface processing is ensured by single-shot ablative modification of the sample surface using radially polarized doughnut-shaped laser pulses with duration of 70 fs. Under such conditions, well reproducible tubular structures are formed whose height is rising with increasing fluence, culminating by closing the structure on the top with formation of a microneedle with a cavity in its base. Upon multi-pulsed irradiation, the height of the needle structures can further increase as compared to those produced by single pulses and top part of the structure is flattened. However, at a certain number of pulses, melting and ablation cause collapsing the entire structure. The mechanisms responsible for creating the tubular and needle structures are discussed based on the careful analysis of the experimental observations. The generated silicon microtubes and needles can find applications in various fields, such as intracellular delivery of micromolecules, micro/electromechanical systems, photovoltaic devices and silicon-based photonics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovsky2022,

title = {Glass formation and properties of the TeO2-ZnO-BaO tellurite optical glasses},

author = {J.Hrabovsky, F.Desevedavy, L.Strizik, G.Gadret, P.Kalenda, B.Frumarova, L.Benes, S.Slang, M.Veis, T.Wagner, F.Smektala},

url = {https://www.sciencedirect.com/science/article/pii/S0022309322000540},

doi = {https://doi.org/10.1016/j.jnoncrysol.2022.121445},

issn = {0022-3093},

year  = {2022},

date = {2022-02-10},

journal = {Journal of Non-Crystalline Solids},

volume = {582},

number = {121445},

pages = {2-9},

abstract = {We report the thorough study on glass forming ability and properties of the TeO2-ZnO-BaO (TZB) optical glasses prepared by the melt-quenching method at 900 °C. The attention has been paid to investigation of thermal, structural, and optical properties of glasses with content of TeO2 from 52.5 up to 90%. The introduction of ZnO and/or BaO into TeO2-based glass results in increase of the glass transition temperature Tg from 319 to 369 °C and decrease of the refractive index and density of prepared glasses. The structure of studied TZB glasses was investigated by Raman scattering. Since the TZB glasses exhibit good thermal stability, wide spectral region of transparency from ultraviolet (UV), λ ≈ 0.35 μm, up to mid-infrared (MIR), λ ≈ 6 μm, wavelengths with high values of refractive index (n1550 ≈ 1.87–2.04), they may be utilized as optical materials, which can be designed on the results presented in this paper.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Docekal2022,

title = {Stereoselective Cyclopropanation of Boron Dipyrromethene (BODIPY) Derivatives by an Organocascade Reaction},

author = {V. Dočekal, T. Koberová, J. Hrabovský, A. Vopálenská, R. Gyepes, I. Císařová, R. Rios, J. Veselý},

url = {https://onlinelibrary.wiley.com/doi/10.1002/adsc.202101286},

doi = {https://doi.org/10.1002/adsc.202101286},

issn = {1615-4169},

year  = {2022},

date = {2022-01-31},

journal = {Advanced Synthesis and Catalysis },

volume = {5},

number = {364},

pages = {930-937},

abstract = {The synthesis of enantiopure chiral boron dipyrromethenes (BODIPYs) is of importance due the intrinsic properties of BODIPYs as fluorophores that could be used as probes for molecular sensing. The present study reports an asymmetric organocatalytic cascade reaction of meso-chloromethyl BODIPY derivatives with α,β-unsaturated aldehydes catalyzed by a chiral secondary amine. The corresponding BODIPY-derived cyclopropanes were produced in isolated yields 66–98%, and with diastereomeric ratios 3/2–>20/1, and 92–99% ee for major diastereomer. The synthetic utility of the protocol was exemplified on a set of additional transformations of the corresponding optically pure compounds. In addition, a study explaining the reaction mechanism (DFT computations) and photophysical characterization of all enantioenriched products were accomplished.},

note = {Very important publication (assigned by Editor) - Front Cover Picture (https://doi.org/10.1002/adsc.202200013)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{dd,

title = {Chemistry Race/Chemiklánı́: Team-Based Competition in Chemistry},

author = {Jan Hrubeš, Adam Tywoniak, Martin Balouch, Stanislav Chvíla, and Jan Hrabovský},

url = {https://pubs.acs.org/doi/10.1021/acs.jchemed.1c00763#.YYR0DK01OmE.twitter},

doi = {https://doi.org/10.1021/acs.jchemed.1c00763},

year  = {2021},

date = {2021-11-04},

journal = {Journal of Chemical Education},

abstract = {Identification and further motivation of gifted students are widely discussed among the science education community. In the context of the educational system of the Czech Republic, competitions serve as one of the main ways to identify those gifted in precollege education. In this article, we report the foundation of a team-based open-book competition in chemistry. The competition targets upper-secondary-school students with an interest in chemistry. We describe the organizational process of the competition, including the selection and reviewing of questions. We discuss the personal requirements for organizing staff, the need to train them adequately, and various ways of supporting them. We explain the scoring system and discuss the score data from years 2016–2020, assessing the difficulty of the question sets and proposing an optimal difficulty profile. The competition has been held concurrently in the Czech Republic and the United Kingdom since 2020 and has the potential for further internationalization.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovský2021,

title = {Optical characterization of Y3Al5O12 and Lu3Al5O12 single crystals},

author = {J. Hrabovský, M. Kučera, L. Paloušová, L. Bi, and M. Veis},

url = {https://www.osapublishing.org/ome/fulltext.cfm?uri=ome-11-4-1218&id=449463},

doi = {https://doi.org/10.1364/OME.417670},

issn = {2159-3930},

year  = {2021},

date = {2021-03-23},

journal = {Optical Materials Express},

volume = {11},

number = {4},

pages = {1218-1223},

abstract = {In this work spectrally dependent optical parameters of nominally pure single crystals of yttrium aluminum garnet (YAG) and lutetium aluminum garnet (LuAG) were studied using spectroscopy ellipsometry together with transmittance measurements in a broad spectral range from 0.73 to 6.42 eV (193–1700 nm). Obtained data in terms of complex refractive index and reflectivity represent an extension of previous studies towards the ultraviolet spectral region and provide a background for the design of a variety of optical applications such as laser host matrix systems, doped luminescence materials, optical imaging devices for semiconductor immersion lithography, construction of scintillators and other devices operating in the ultraviolet spectral region. A complete database of obtained optical parameters (real and imaginary parts of complex refractive index) in the whole spectral range is included in the supplementary part.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Liberatore_2019,

title = {ANTENNA-LIKE EFFECT INDUCED BY SURFACE DEFECTS UPON ULTRASHORT LASER NANOSTRUCTURING OF SILICON},

author = {Chiara Liberatore, Jan Hrabovsky, Inam Mirza, Alexander V Bulgakov, Nadezhda M Bulgakova},

doi = {10.17973/MMSJ.2019_12_2019105},

issn = {1805-0476},

year  = {2019},

date = {2019-01-01},

journal = {MM Science Journal},

volume = {5},

pages = {3594-3597},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovsky_2019,

title = {SURFACE STRUCTURING OF KAPTON POLYIMIDE WITH FEMTOSECOND AND PICOSECOND IR LASER PULSES},

author = {Jan Hrabovsky, Chiara Liberatore, Inam Mirza, Juraj Sladek, Jiri Beranek, Alexander Bulgakov V and Nadezhda M Bulgakova},

url = {http://www.dl.begellhouse.com/journals/728e68e739b67efe,0032c6013bb79bd6,486fb58e2d1603fe.html},

issn = {2169-2785},

year  = {2019},

date = {2019-01-01},

journal = {Interfacial Phenomena and Heat Transfer},

volume = {7},

number = {2},

pages = {113-121},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1007/s10854-017-6363-2,

title = {Quadrature frequency resolved spectroscopy of upconversion photoluminescence in GeGaS:Er3+; II. elucidating excitation mechanisms of red emission besides green emission},

author = {Aoki T., Strizik L., Hrabovsky J., Wagner T.},

url = {https://doi.org/10.1007/s10854-017-6363-2},

doi = {10.1080/09500839.2015.1091968},

year  = {2017},

date = {2017-01-01},

journal = {J Mater Sci: Mater Electron},

volume = {28},

pages = {7077–7082},

publisher = {Springer},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1007/s10854-016-6306-3,

title = {Quadrature frequency resolved spectroscopy of upconversion photoluminescence in GeGaS:Er3+: I. Determination of energy transfer upconversion parameter},

author = {Strizik L., Prokop V., Hrabovsky J., Wagner T., Aoki T. },

url = {https://doi.org/10.1007/s10854-016-6306-3},

doi = {10.1080/09500839.2015.1091968},

year  = {2017},

date = {2017-01-01},

journal = {J Mater Sci: Mater Electron},

volume = {28},

pages = {7053–7063},

publisher = {Springer},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1080/09500839.2015.1091968,

title = {Dynamics of upconversion photoluminescence in Ge–Ga–S: Er3+: application of quadrature frequency resolved spectroscopy},

author = {L Strizik and J Hrabovsky and T Wagner and T Aoki},

url = {https://doi.org/10.1080/09500839.2015.1091968},

doi = {10.1080/09500839.2015.1091968},

year  = {2015},

date = {2015-01-01},

journal = {Philosophical Magazine Letters},

volume = {95},

number = {9},

pages = {466-473},

publisher = {Taylor & Francis},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hrabovsky_2013,

title = {Rare-earth-doped amorphous chalcogenides in photonics},

author = {J. Hrabovsky, Wagner T., L. Strizik},

url = {https://iafastro.directory/iac/archive/browse/IAC-13/C2/8/18343/},

year  = {2013},

date = {2013-01-01},

journal = {Proceedings of the International Astronautical Congress, IAC},

volume = {8},

pages = {106314},

keywords = {},

pubstate = {published},

tppubtype = {article}

}