Lithuanian Journal of Physics最新文献_第9页

The formation of self-assembled structures of C60 in solution and in the volume of an evaporating drop of a colloidal solution 在溶液中和在胶体溶液的蒸发滴的体积中形成C60的自组装结构

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-08-03 DOI: 10.3952/physics.v60i3.4306

U. Makhmanov, A. Kokhkharov, S. Bakhramov, D. Erts

{"title":"The formation of self-assembled structures of C60 in solution and in the volume of an evaporating drop of a colloidal solution","authors":"U. Makhmanov, A. Kokhkharov, S. Bakhramov, D. Erts","doi":"10.3952/physics.v60i3.4306","DOIUrl":"https://doi.org/10.3952/physics.v60i3.4306","url":null,"abstract":"The results of experiments on the self-aggregation of C60 fullerene molecules both inside a two-component solvent (xylene/tetrahydrofuran) and in the volume of an evaporating drop of C60 colloidal solution on a flat substrate surface are presented. The investigations of C60 solutions using dynamic light scattering, transmission electron microscopy and UV–Vis absorption spectroscopy methods revealed the possibility of synthesis of fractal nanoaggregates with a diameter of up to ~135 nm at low concentrations of C60 in the solutions. The final geometric dimensions of C60 nanoaggregates were determined by the initial concentration of fullerene in the solvent medium. Using the scanning electron microscopy method, we have shown that in an open dissipative system – in the volume of an evaporating droplet of the colloidal solution of fullerene C60 sessile on the surface of a flat glass substrate, large quasispherical nanoaggregates with an average diameter of ~380–800 nm are formed. The physical features and regularities that characterize the processes of self-aggregation of fullerene particles in the volume of a drying drop were determined.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44215715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Photoluminescence properties of hybrid perovskites in solar cells with TiO2 and Mg0.2Zn0.8O electron transport layers 具有TiO2和Mg0.2Zn0.8O电子传输层的太阳能电池中杂化钙钛矿的光致发光特性

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-08-03 DOI: 10.3952/physics.v60i3.4304

A. Cerskus, S. Ašmontas, K. Petrauskas, A. Sužiedėlis, J. Gradauskas, A. Opanasyuk, B. Vengalis

引用次数: 0

A physical mechanism of sensitivity enhancement of organic X-ray detectors with tungsten nanoparticles 纳米钨增强有机X射线探测器灵敏度的物理机制

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4225

A. Poškus, Rokas Dobužinskas, M. Viliunas, K. Arlauskas

{"title":"A physical mechanism of sensitivity enhancement of organic X-ray detectors with tungsten nanoparticles","authors":"A. Poškus, Rokas Dobužinskas, M. Viliunas, K. Arlauskas","doi":"10.3952/physics.v60i2.4225","DOIUrl":"https://doi.org/10.3952/physics.v60i2.4225","url":null,"abstract":"A simple theoretical model explaining the increase of X-ray sensitivity caused by adding tungsten nanoparticles into thin layers of organic materials is proposed. The mentioned increase of sensitivity is caused by quenched electron multiplication due to secondary electron emission from tungsten particles. After some simplifying assumptions, an expression of the electron multiplication factor K is derived for the case when tungsten atoms are uniformly mixed with the matrix material. The main assumption of the model is the existence of a threshold energy Emin of the order of 0.1 eV, below which the recombination of charge carriers prevents them from being accelerated by the electric field to energies sufficient for impact ionization. It is shown that this assumption makes the increase of K and photocurrent with increasing electric field much slower than the exponential increase commonly associated with an electron avalanche, and K may even start to decrease when the electric field strength exceeds a certain value. Another factor, which has an adverse effect on the X-ray sensitivity, is the ionization energy loss of photoelectrons inside metallic nanoparticles. The results of Monte Carlo simulations show that in the case of spherical tungsten particles with 0.8 μm diameter, the latter phenomenon may cause an additional decrease of the sensitivity by as much as 75%. In order to reduce this effect, the size of nanoparticles should be reduced, or, alternatively, most of the photoelectrons should be generated in the organic matrix rather than inside the nanoparticles.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46725483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

27Al MAS NMR spectroscopy study of Eu2+-doped and Dy3+-co-doped SrAl4O7 Eu2+掺杂和Dy3+共掺杂SrAl4O7的27Al MAS NMR研究

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4224

M. Misevicius, L. Dagys, A. Marsalka, Kristina Kristinaityte, V. Balevičius

{"title":"27Al MAS NMR spectroscopy study of Eu2+-doped and Dy3+-co-doped SrAl4O7","authors":"M. Misevicius, L. Dagys, A. Marsalka, Kristina Kristinaityte, V. Balevičius","doi":"10.3952/physics.v60i2.4224","DOIUrl":"https://doi.org/10.3952/physics.v60i2.4224","url":null,"abstract":"The Eu2+-doped strontium aluminate SrAl4O7 samples have shown the blue-green persistent luminescence at 490 nm while the co-doping with Dy3+ shifts the maximum of emission to 475 nm. Undoped, 3% Eu-doped and 6% Dy-co-doped SrAl4O7 samples were prepared by the solid state-reaction method and studied by the solid-state 27Al MAS NMR applying the single pulse-acquire and Hahn-echo pulse sequences. It was shown that the Eu2+ with Dy3+ ion doping did not affect the bulk structure as well as the local Al environment in SrAl4O7. This means that large shifts of the emission maximum cannot be caused by changes in the local environment upon the co-doping of SrAl4O7:Eu2+ with Dy3+. However, the spectral features observed in the range between the signals of 4- and 6-coordinated Al (20–40 ppm) indicate that certain phase imperfections are present in all studied samples, and most probably amorphous/glassy domains were formed. Note that such amount of phase impurities was not detected by standard XRD or FTIR methods. This has revealed the 27Al MAS NMR technique to be a very effective tool monitoring the phase perfectness in series of strontium aluminate samples.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44499735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of vertebral degeneration on the instability of spine 脊椎退变对脊柱不稳定性的影响

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4228

Olga Chabarova, R. Kačianauskas, V. Alekna

引用次数: 0

Depopulation mechanism for incoherent terahertz source – THz torch – based on GaAsBi/GaAs quantum well in GaAs/AlGaAs parabolic quantum well GaAs/AlGaAs抛物量子阱中基于GaAsBi/GaAs量子阱的非相干太赫兹源太赫兹炬的退布居机制

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4226

M. Karaliūnas, A. Udal, G. Valušis

引用次数: 3

Quantum paraelectricity and induced ferroelectricity by germanium doping of (PbySn1–y)2P2S(Se)6 single crystals 锗掺杂（PbySn1–y）2P2S（Se）6单晶的量子顺电性和感应铁电性

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-04-28 DOI: 10.3952/physics.v60i2.4227

I. Zamaraite, A. Dziaugys, Y. Vysochanskii, J. Banys

引用次数: 1

Activation of high flux test module sample holder after IFMIF-DONES operation IFMIF-DONES操作后高通量测试模块样品支架的激活

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4161

S. Breidokaite, G. Stankūnas, A. Tidikas

{"title":"Activation of high flux test module sample holder after IFMIF-DONES operation","authors":"S. Breidokaite, G. Stankūnas, A. Tidikas","doi":"10.3952/physics.v60i1.4161","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4161","url":null,"abstract":"Nuclear safety assessment in nuclear fusion devices relies on the Monte Carlo method based neutron transport calculations. This paper presents information about the calculation results of the activities and dose rates caused by neuron irradiation for the structural materials of the high flux test module sample holder of IFMIF-DONES. The neutron induced activities and dose rates at shutdown were calculated by means of the FISPACT-2010 code with data from the EAF-2010 nuclear data library. Neutron fluxes and spectra were obtained with MCNP neutron transport calculations. The activities and dose rates were calculated at the end of irradiation of the assumed device operation scenario for cooling times of 0 s – 1000 year. In addition, radionuclides with contribution of at least 0.5% to the total value of activation characteristics at the previously mentioned cooling times were identified. After the operation, the most active radionuclide is 55Fe, with an activity share ranging from 30% (M200) to 63% (M8), and at the end of the prediction it accounts for 86% of the total activity. The highest dose rates at the end of irradiation are attributed to 56Mn radionuclide. 54Mn and 60Co are the most dominant radionuclides during intermediate and long cool-down periods.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49374045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Black silicon quality control by conditions of nickel-assisted etching of crystalline silicon surfaces in photovoltaic devices 用镍辅助蚀刻光电器件中晶体硅表面的条件控制黑硅质量

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4164

M. Kamarauskas, M. Treideris, V. Agafonov, A. Mironas, V. Strazdienė, A. Rėza, A. Šetkus

{"title":"Black silicon quality control by conditions of nickel-assisted etching of crystalline silicon surfaces in photovoltaic devices","authors":"M. Kamarauskas, M. Treideris, V. Agafonov, A. Mironas, V. Strazdienė, A. Rėza, A. Šetkus","doi":"10.3952/physics.v60i1.4164","DOIUrl":"https://doi.org/10.3952/physics.v60i1.4164","url":null,"abstract":"Here we present a study of the nickel-assisted etching applied to form uniform black silicon layers on crystalline silicon substrates. We related the parameters used for technological process control (etchant, nickel thickness) to parameters of the obtained surface and explain the correlation using the etching model responsible for etching of the silicon covered by a thin nickel film. The increase in the thickness of the metal catalyst did not suppress the etching completely but allowed one to tune the roughness of the silicon surface. The rate of the electrochemical etching was additionally changed by adaptation of the proportion of components in the complex etchant. Depending on the intentionally selected conditions, the duration of the optimized process was from 3 to 10 min. The lowest optical reflection commonly accepted as the black silicon surface was obtained for the mixture with a low amount of the active etchant component. It was demonstrated that the method is acceptable to improve the characteristics of a photovoltaic cell.","PeriodicalId":18144,"journal":{"name":"Lithuanian Journal of Physics","volume":" ","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47848466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of meta substitution of methyl group on 2-hydroxypyridine: Spectroscopic investigation 甲基间位取代对2-羟基吡啶的影响:光谱研究

IF 0.6 4区物理与天体物理

Lithuanian Journal of Physics Pub Date : 2020-02-05 DOI: 10.3952/physics.v60i1.4162

A. Srivastava, S. Saxena

引用次数: 2