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  1. 3 Open Physics
  2. 2 Inżynieria Materiałowa
  3. 2 JAMRIS
  4. 2 Journal of Achievements in Materials and Manufacturing Engineering
  5. 2 Journal of Automation Mobile Robotics and Intelligent Systems
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  1. 1 2022
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  4. 3 2010
  5. 5 2009
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  1. 2 Asai K.
  2. 2 Ikeda H.
  3. 2 Salleh F.
  4. 2 Wendler B.
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1
Content available remote Hydrostatic extrusion of titanium - process parameters
100%
Topolski K. , Garbacz H. , Pachla W. , Kurzydłowski K. J.
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2007
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tom Vol. 7, nr 4(14)
114-120
EN
Hydrostatic extrusion (HE), which belongs to the severe plastic deformation (SPD) techniques, permits producing titanium with a nano-crystalline structure. The homogeneity of the microstructure, the volume of the product and also the quality of its surface depend on the parameters of the hydrostatic extrusion process. The study was concerned with the effects of the deformation magnitude and the number of the HE cycles upon the microstructure and mechanical properties of the titanium being treated. The course of the HE process and its final product appeared to depend greatly on the process temperature and the starting state of the titanium surface. The results obtained during the experiments permitted optimizing the HE process, and improving the performance and mechanical properties of the final product.
2
Content available remote Point-by-point inscription of 250-nm-period structure in bulk fused silica by tightly-focused femtosecond UV pulses: experiment and numerical modeling
100%
Nikogosyan D. , Dubov M. , Schmitz H. , Mezentsev V. , Bennion I. , Bolger P. , Zayats A.
Open Physics
|
2010
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tom 8
|
nr 2
169-177
EN
By conducting point-by-point inscription in a continuously moving slab of a pure fused silica at the optimal depth (170 μm depth below the surface), we have fabricated a 250-nm-period nanostructure with 30 nJ, 300 fs, 1 kHz pulses from frequency-tripled Ti:sapphire laser. This is the smallest value for the inscribed period yet reported, and has been achieved with radical improvement in the quality of the inscribed nanostructures in comparison with previous reports. The performed numerical modeling confirms the obtained experimental results.
3
Content available remote Using stability analysis of discrete elastic systems to study the buckling of nanostructures
100%
Korobeynikov S. N. , Alyokhin V. V. , Annin B. D. , Babichev A. V.
|
2012
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tom Vol. 64, nr 4
367-404
EN
Stability/instability criteria of discrete elastic systems are used to study the buckling of nanostructures. The deformation of nanostructures is simulated by solving the nonlinear equations of molecular mechanics. The external forces applied to the nanostructure are assumed to be dead (that is the directions of their action remain constant throughout nanostructure deformation). We note that the positive-definiteness property of the tangential stiffness matrix of a nanostructure is a universal sufficient stability criterion for both equilibrium states and quasi-static/dynamic motions of the nanostructure. The equilibrium configurations are stable in Lyapunov's sense, and quasi-static/dynamic motions are stable in a finite time interval t "isin" (0, Tcr) in which the positive-definiteness property of this matrix is preserved. For dynamic motions of nanostructures, the stability property in this time interval follows from Lee’s criterion of quasi-bifurcation of solutions of second order ODEs. The non-positive definiteness of the tangential stiffness matrix of nanostructures at a time t > Tcr corresponds to both unstable equilibrium configurations and unstable dynamic motions. Computer procedures for determining the critical time and buckling mode(s) are developed using this criterion and are implemented in the PIONER FE code. This code is used to obtain new solutions for the deformation and buckling of twisted (10, 10) armchair and (10, 0) zigzag single-walled carbon nanotubes
4
Size-dependent properties of nanostructured metal particles
100%
Schmid G.
|
1998
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tom Vol. 46, No. 3
229-235
EN
Ligand stabilized transition metal clusters exhibit size-dependent electronic behaviour. From the current-voltage characteristics of a 17 nm Pd cluster it can be followed that it behaves bulk-like at room temperature, but shows a Coulomb blockade at 4.2 K. Contrary to that, 1.4 nm Au clusters show a Coulomb blockade already at room temperature and a series of single electron transitions at 90 K. Quantum size behaviour of a series of Pd clusters is also demostrated by specific heat and susceptibility measurements. Activation energies for electron transitions between three-dimensionally organized 1.4 nm gold clusters, separated by spacer molecules of varying lengths, have been determined. Nanoporous alumina membranes serve as matrices to generate cluster wires which will be used to study electron transitions between clusters in one dimension.
5
Content available Impurity-concentration dependence of seebeck coefficient in silicon-on-insulator layers
100%
Salleh F. , Asai K. , Ishida A. , Ikeda H.
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2009
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tom Vol. 3, No. 4
134-136
EN
We measured the Seebeck coefficient of P-doped ultrathin silicon-on-insulator (SOI) layers with thicknesses of 6-100 nm. The dependence of the coefficient on the impurity concentration was investigated, and was shown to be in good agreement with that of bulk Si. In addition, it was found to decrease with increasing impurity concentration, as is usual in semiconductor materials. However, for doping levels above 3.5x1019 cm-3, the Seebeck coefficient was observed to increase. This is likely to be due to the influence of an impurity band.
6
Content available Seebeck coefficient measurement by Kelvin-probe force microscopy
100%
Ikeda H. , Salleh F. , Asai K.
|
2009
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tom Vol. 3, No. 4
49-51
EN
In order to measure the Seebeck coefficient of nanometer-scale thermoelectric materials, we propose a new technique in which the thermoelectric-motive force (TEMF) is evaluated by Kelvin-probe force microscopy (KFM). In this study, we measured the Seebeck coefficient of an n-type Si wafer. The surface-potential difference between the high- and low-temperature regions on the Si wafer increases with increasing temperature difference. This indicates that the TEMF can be measured by KFM. The Seebeck coefficient evaluated from the surface-potential difference is 0.71š0.08 mV/K, which is close to that obtained by the conventional method.
7
Content available remote Synthesis and characterization of nanostructured molybdenum & tungsten carbide materials, and study of diffusion model
88%
Covington L. , Munirathinam K. , Islam A. , Roberts K.
Polish Journal of Chemical Technology
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2012
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tom 14
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nr 1
28-34
EN
Powders of two molybdenum carbides (Mo2C and MoC1-x) and tungsten carbide (WC) were prepared by means of temperature programmed reaction (TPR) method. Mo2C and MoC1-x were synthesized by reacting MoO3 with a preselected molar ratio of methane/hydrogen and carbon monoxide/hydrogen gas mixtures respectively. WC was prepared using tungsten oxide (WO3) and a methane/hydrogen gas mixture. These carbides were ultrasonically dispersed in de-ionized water. Samples were characterized using room temperature x-ray diffraction and scanning microscopy. A kinetic diffusion model is also studied to determine diffusivities in solids where the diffusing species desorbs or reacts at the external surfaces, and where the diffusivity does not vary appreciably with concentrations. The method involves measuring the flux of the diffusive species into the solid under the influence of a temperature program.
8
Content available remote Pulsed laser treatment of gold and black gold thin films fabricated by thermal evaporation
88%
Novotný M. , Fitl P. e. , Sytchkova A. , Bulíř J. Ã. , Lanaok J. , Pokorna P. , Najdek D. , Boan J.
Open Physics
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2009
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tom 7
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nr 2
327-331
EN
The effect of pulsed laser treatment of metal, and metal blacks, was studied. Gold and black gold thin films were fabricated by thermal evaporation of gold in a vacuum and nitrogen atmosphere respectively. Black gold films were grown in a nitrogen atmosphere at pressures of 200 Pa and 300 Pa. UV pulsed laser radiation (λ = 266 nm, τ = 4 ns), with fluence ranging from 1 mJ·cm−2 to 250 mJ·cm−2 was used for the film treatment in a vacuum and nitrogen atmosphere. The nitrogen pressure was varied up to 100 kPa. Surface structure modifications were analyzed by optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDX) was used for chemical characterization of the samples. A significant dependence of the film optical and structural properties on laser treatment conditions (laser fluence, ambient pressure and number of applied pulses) was found. The threshold for observable damage and initiation of changes of morphology for gold and black gold surfaces was determined. Distinct modifications were observed for fluences greater than 106 mJ·cm−2 and 3.5 mJ·cm−2 for the gold and black gold films respectively. Absorbtivity of the black gold film is found to decrease with an increase in the number of laser pulses. Microstructural and nanostructural modifications after laser treatment of the black gold film were observed. EDX analysis revealed that no impurities were introduced into the samples during both the deposition and laser treatment.
9
Geneza i kierunki rozwoju nanotechnologii
75%
Kotnarowski A.
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2011
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tom nr 6
PL
W artykule przedstawiono genezę, obserwowanego w ostatnich latach, dynamicznego rozwoju nanotechnologii na świecie, zapoczątkowanego w Stanach Zjednoczonych ze względu na największe skupienie potencjału naukowego i kapitałowego. Omówiono rodzaje nanomateriałów i ich już wdrożone zastosowania techniczne, przede wszystkim w dziedzinach: elektroniki, informatyki i medycyny, a także przewidywane, możliwe zastosowania, będące obecnie przedmiotem badań. Ponadto przedstawiono krótkoterminową prognozę rozwoju nanotechnologii. Zaprezentowano także badania własne autora w obszarze tribologii, polegające na stosowaniu nanocząstek metali, jako dodatków modyfikujących tribologiczne właściwości środków smarowych.
EN
The paper presents a genesis of observed in last years dynamic development of nanotechnology originated in USA because of biggest concentration of scientific and capital potential. Types of nanomaterials are discussed and their technical applications first of all in the fields of electronics, informatics and medicine, and also predicted, possible applications which are now in examinations are presented. A short term prognosis of nanotechnology development is presented as well. On above background the author own examinations are showed also in the area of tribology, consisting in metal nanoparticles using as additives modifying tribological properties of lubricating and cutting oils.
10
Content available remote Warstwy ochronne TiN na stopach magnezu wytwarzane metodą PAPVD
75%
Gołąbczak M. , Wendler B. , Pawlak W.
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2007
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tom R. 12, z. 4
31-41
PL
W artykule przedstawiono zmodyfikowaną technologię wytwarzania powłok ochronnych i dekoracyjnych z TiN na stopach magnezu, polegającą na zastosowaniu zmodyfikowanej metody PAPVD (Plasma Activated Physical Vapour Deposition). Zaprezentowano opis stanowiska badawczego do realizacji tej technologii oraz wyniki badań, dotyczące oceny właściwości użytkowych wytworzonych powłok ochronno-dekoracyjnych na stopie magnezu AZ31. Prezentowane wyniki badań dotyczą pomiaru mikrotwardości i modułu Younga wytworzonych powłok, oceny morfologii oraz mikro- i nanostruktury geometrycznej powierzchni tych warstw na stopie magnezu AZ 31.
EN
In the paper a new technology for manufacturing of protective and decorative TiN coatings on magnesium alloys consisting in use of modified PAPVD (Plasma Activated Physical Vapour Deposition) method has been presented. Also investigation stand for realization of this technology and investigation results concerning properties of manufactured protective and decorative coatings on AZ31 magnesium alloy has been depicted. Presented investigation results concern measurement of nanohardness and Young modulus of manufactured coatings, morphology and geometrical micro- and nanostructure of surfaces of these coatings on AZ31 magnesium alloy.
11
Content available remote Nanotechnology impact towards biomedical engineering
63%
Kikuchi M.
|
|
tom Vol. 27, no. 1-2
27-32
EN
Nanotechnology is emerging as a new field enabling the creation and application of materials, devices, and systems at atomic and molecular levels and the exploitation of novel properties that emerge at the nanometer scale. In this paper the author shows the nivel approach to photodynamic therapy (PDT) by adopting the polymeric micelle encapsulating dendrimer phtalocyanine.
12
Content available remote Microstructure and properties of dynamically compressed copper Cu99.99
63%
Leszczyńska-Madej B. , Richert M.
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2010
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tom Vol. 39, nr 1
35-42
EN
Purpose: The main object of this study is to establish the influence of dynamic compression on the possibility of microstructure refinement in polycrystalline copper Cu99.99. Design/methodology/approach: Polycrystalline copper Cu99.99 was dynamically compressed on a falling - weight - type impact machine with strain rate ranging from 1.75×102 to 2.7×102 s-1. After deformation, the samples were tested for microhardness and their microstructure was examined by means both optical and electron microscopy. Additionally, the width of microbands observed in the microstructure was statistically evaluate by using mean chord method. The misorientation of selected microstructural elements was determined using proprietary KILIN software. Findings: It was found that to produce materials with nanometric features is not only possible by exertion of severe plastic deformation methods (SPD) but also by deformation with moderate strains and high strain rates. The demonstrated data show, that in some range the amount of deformation and strain rate can be interchangeable parameters causing similar structural effects.n. Practical implications: The results may be utilized for determination of a relation between microstructure and properties of the copper in the process of dynamic compression. Originality/value: The results contribute to evaluation properties of the polycrystalline copper in the light of achievement of fine – grained microstructure. The obtained results indicated that dynamic compression with high strain rate can be an effective method for microstructure refinement, comparable with SPD methods
13
Content available remote Erosion and abrasion wear resistance of GMA wire surfaced nanostructural deposits
63%
Klimpel A. , Kik T.
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2008
|
tom Vol. 30, nr 2
121-124
EN
Purpose: Purpose of this study was to find influence of chemical composition, structure and hardness of modern metal cored wire deposits on their hardness and erosion and abrasion wear resistance of three different wires which gives the nanostructural deposits. Design/methodology/approach: Methodology surfaced deposits were investigated by macro- and microscope observations, hardness tests, erosion wear resistance test and abrasive wear resistance test. Findings: wire which gives highest hardness, erosion wear resistance and abrasive wear resistance deposits was indicated. Research limitations/implications: Information aobut an influence of chemical composition of nanostructural deposit filler materials on hardness, erosion wear resistance and abrasive wear resistance of these deposits. Practical implications: Results of this paper are the informations for industrial partners how we can change properties of modern deposits and possibilities of surfacing process steering. Originality/value: the researches were provided using newest filler material for GMA surfacing of high quality nanostructural deposits.
14
Content available remote Badania materiałów do przechowywania wodoru w Wojskowej Akademii Technicznej
63%
Bystrzycki J. , Polański M. , Perzyna K.
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2007
|
tom Vol. 60, nr 1
19-20
PL
W artykule przedstawiono badania w obszarze wodorków metali prowadzone w Wojskowej Akademii Technicznej. Wodorek magnezu jest bardzo atrakcyjnym materiałem do przechowywania wodoru, ponieważ jest lekki, tani i posiada wysoką pojemność. Jednak, praktyczne zastosowanie wodorku magnezu jest ograniczone z powodu złej kinetyki procesu absorpcji i desorpcji wodoru. Nasze ostatnie wyniki badań pokazują, że problem ten można rozwiązać wytwarzając wodorek magnezu o budowie nanokrystalicznej z dodatkiem katalizatora o wielkości nanometrycznej.
EN
This paper presents research efforts carried out in the Military University of Technology in the area of metal hydrides. Magnesium hydride is very attractive hydrogen storage material because of its high capacity, lightweight and low cost. However, its practical use is limited by poor hydrogen absorption and desorption kinetics. Our recent results have shown that this problem can be resolved by synthesis of nanocrystalline magnesium hydride with nanosized catalyst.
15
Content available Nanostructuring in powder metallurgy and forging technologies
63%
Leshchynsky V. , Wiśniewska-Weinert H.
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2008
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tom T. 19, nr 4
19-28
EN
In recent years, near-nano (submicron) and nanostructured materials have attracted more and more attention from the materials community. Nanocrystalline materials are characterized by a microstructural length or grain size of up to about 100 nm. Materials having grain size of 0.1-0.3 mm are classified as submicron materials. Nanocrystalline materials possess unique mechanical properties. When the grain size is below a critical value (10-20 nm), more than 50% (by volume) of atoms is associated with grain boundaries or interfacial boundaries. In this respect, dislocation pile-ups cannot form, and the Hall-Petch relationship for conventional coarse-grained materials is no longer valid. Therefore, grain boundaries play a major role in the structure formation of nanocrystalline materials. Nanocrystalline materials exhibit creep and super plasticity at lower temperatures than conventional micro-grained counterparts. In this review paper, current developments in fabrication, microstructure, physical and mechanical properties of nanocrystalline and submicron materials made by Powder Metallurgy and Forging techniques will be addressed. Particular attention is paid to the properties characterization of submicron composites.
PL
W ostatnich latach coraz większym zainteresowaniem materiałoznawców cieszą się materiały prawie nanostrukturalne (submikronowe) i nanostrukturalne. Materiały nanokrystaliczne charakteryzują się mikrostrukturalną długością i wielkością ziaren do 100 nm. Materiały o wielkości ziarna 0,1-0,3 mm klasyfikowane są jako materiały submikronowe. Materiały nanokrystaliczne posiadają unikalne własności mechaniczne. Gdy wielkość ziarna jest poniżej wartości krytycznej (10-20 nm), ponad 50% (objętościowo) atomów związanych jest z granicami ziaren lub granicami międzyfazowymi. W tej sytuacji nie mogą powstawać nawarstwienia dyslokacyjne i zależność Hall-Petch obowiązująca dla konwencjonalnych materiałów gruboziarnistych nie ma już zastosowania. Zatem, granice ziaren odgrywają ważną rolę w tworzeniu struktury materiałów nanokrystalicznych. Materiały nanokrystaliczne wykazują pełzanie i nadplastyczność w niższych temperaturach niż ich konwencjonalne odpowiedniki mikroziarniste. W tym przeglądzie kierujemy uwagę na bieżące postępy w wytwarzaniu: mikrostrukturę, własności fizyczne i mechaniczne materiałów nanokrystalicznych wytwarzanych technikami metalurgii proszków i kucia. Szczególną uwagę zwraca się w tej pracy na własności kompozytów submikronowych.
16
Content available remote Characterisation of nanostructured copper - WC materials
63%
Stobrawa J. P. , Rdzawski Z. M.
|
2009
|
tom Vol. 32, nr 2
171-178
EN
Purpose: The aim of this work was to determine the microstructure and properties stability of nanocrystalline copper dispersion hardened with nanoparticles of tungsten carbides. Design/methodology/approach: Tests were made with Cu and Cu – WC micro – composites containing up to 3% of a hardening phase. The materials were fabricated by powder metallurgy techniques, including milling of powders, followed by their compacting and sintering. The main mechanical properties of the materials were determined from the compression test, and, moreover, measurements of the HV hardness and electrical conductivity have been made. Analysis of the initial nanocrystalline structure of these materials was made and its evolution during sintering was investigated. Findings: It was found that an addition of up to 1.5 wt % of a WC significantly improves mechanical properties of the material and increases its softening point. Research limitations/implications: The powder metallurgy techniques make it possible to obtain nanocrystalline copper-based bulk materials. Additional operations of hot extrusion are also often used. There is some threat, however, that during high temperature processing or application these materials this nanometric structure may become unstable. Practical implications: A growing trend to use new copper-based functional materials is observed recently world-wide. Within this group of materials particular attention is drawn to those with nanometric grain size. Originality/value: The paper contributes to the determination of WC nanoparticles content on the mechanical properties and the nanostructure stability of Cu-WC micro-composites.
17
Content available remote Analysis of grain size effect on tensile properties of Ni3Al - based intermetallic strips
63%
Jóźwik P. , Bojar Z.
|
2007
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tom Vol. 52, iss. 2
321-327
EN
The results of investigation of grain size effect on mechanical properties of Ni3Al – based intermetallic strips measured in a tensile test at room temperature in air have been shown in the paper. Thin intermetallic strips with average grain size of 1, 5, 7, 26, 43 and 83 micrometers prepared by cold rolling and heat treatment at parameters chosen on the basis of our earlier completed recrystallization maps have been used for tensile tests. It has been stated that increasing of basic γ’ phase grain refinement caused intensive increase of tensile yield strength (TYS) and lower increase of ultimate tensile strength (UTS). The highest effectiveness of grain boundary strengthening has been found for average grain size up to 10 micrometers and was connected with a strong reduction of intermetallic material plasticity as well with increasing of its elasticity finding expression in TYS/UTS ratio. However, even for extremely fine-grained Ni3Al sample (average grain size approximately 1 micrometer) a value of ultimate tensile elongation obtained at room temperature in air (“hard conditions” for intermetallic alloys sensitive to environmentally influenced brittleness) was still high – approximately 30% at tensile yield strength above 1200 MPa. The results obtained (for recrystallized Ni3Al) were much better then those for appropriate alloys described in literature. In the analyzed grain size range, a classic exponential dependence of yield strength on average grain size was confirmed. Tension test results were in good correlation with fracture structure. It has been stated that fractures of samples with different grain size were quite similar and mixture-type. There was cleavage fracture via micro-volume of each grain, related to ductile fracture via microregions along grain boundaries. For all tested range of grain sizes a fraction of ductile fracture microregions was high, but higher for coarse-grained samples with ultimate elongation ran into 70%. A dependence of a phase structure (a fraction of γ disordered phase) and degree of γ’ phase ordering on mechanical properties and fracture in a tensile test at room temperature in air was also discussed in the paper.
PL
W pracy przedstawiono wyniki badań wpływu wielkości ziarna na parametry wytrzymałościowe taśm ze stopu na osnowie fazy międzymetalicznej Ni3Al mierzone w próbie statycznego rozciągania, w temperaturze pokojowej, w atmosferze powietrza. Po szczegółowej analizie morfologii budowy ziarnowej materiału w stanie po wygrzewaniu rekrystalizującym prowadzonym przy wykorzystaniu map rekrystalizacji opracowanych we wcześniejszych badaniach do analizy wybrano próbki o średniej wielkości ziarna: 1 µm, 5 µm, 7 µm, 26 µm, 43 µm i 83 µm. Stwierdzono, wraz ze wzrostem stopnia rozdrobnienia fazy γ’ stanowiącej osnowe badanego materiału, intensywny przyrost granicy plastyczności oraz mniej intensywny przyrost doraźnej wytrzymałości na rozciąganie. Wykazano, że największa skuteczność umocnienia granicami ziaren (poprzez rozdrobnienie ziarna) ma miejsce w przedziale wielkości ziarna do ok. 10 µm, co odpowiada jednocześnie, zachodzącemu równolegle intensywnemu zmniejszeniu plastyczności materiału i zwiększeniu jego „wydolności sprężystej” wyrażonej stosunkiem Re/Rm. Jednak nawet dla skrajnie drobnoziarnistego stopu (średnia sśednica ziarna około 1 µm) wydłużenie uzyskiwane w próbie rozciągania prowadzonej w temperaturze otoczenia w powietrzu (bardzo ważne czynniki ”obciążające” wyniki uzyskiwane dla próbek stopów intermetalicznych) jest bardzo wysokie, bo bliskie 30%, przy także wysokiej granicy plastyczności powyżej 1200 MPa. Uzyskane wyniki, dla stopu w stanie równowagowym (po rekrystalizacji), są nieporównywalnie korzystniejsze od odpowiadajacych im nielicznych danych dostępnych w literaturze. Potwierdzono także, w rozpatrywanym przedziale wielkości ziarna, ”klasyczny” przebieg wykładniczej zależności granicy plastyczności od wielkości ziarna. Wyniki badań statycznego rozciągania korespondują z budową fraktograficzną powierzchni przełomów. Stwierdzono, że przełomy badanego stopu w stanie bez umocnienia ale przy zróżnicowanej wielkości ziarna wykazują wiele wspólnych cech budowy – są efektem pękania łupliwego w mikroobszarach i pękania ciągliwego stref granic ziaren, natomiast różnią się udziałem obu tych składowych. Przełomy badanego stopu, w całym rozpatrywanym przedziale wielkości ziarna, charakteryzują się dużym udziałem odkształcenia plastycznego w granicach ziaren – zauważalnie większym dla ziarna o większych rozmiarach pozwalającym na uzyskanie wydłużenia równomiernego na poziomie 70%. Dyskutowano także problem wpływu budowy fazowej (udział nieuporządkowanej fazy γ) oraz zmian stopnia uporzadkowania podstawowej fazy γ’ na właściwości mechaniczne i budowe przełomów w próbkach po rozciąganiu w temperaturze pokojowej, w atmosferze powietrza.
18
Spektroskopia modulacyjna nanostruktur półprzewodnikowych w zakresie bliskiej i średniej podczerwieni
63%
Misiewicz J. , Motyka M. , Sęk G. , Kudrawiec R.
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2009
|
tom Vol. 50, nr 5
78-83
PL
W pracy przedstawiono wybrane rezultaty badań spektroskopowych realizowanych w Zespole Optycznej Spektroskopii Nanostruktur Instytutu Fizyki Politechniki Wrocławskiej prowadzonych w zakresie bliskiej i średniej podczerwieni. Przedstawiono możliwości jakie daje stosowanie spektroskopii modulacyjnej do wyznaczania parametrów istotnych przy konstruowaniu urządzeń takich jak np.: lasery półprzewodnikowe. W pierwszej części przedstawiono wyniki badań struktur przeznaczonych na zakres drugiego i trzeciego okna telekomunikacyjnego (1,3...1,55 μm) głównie studni, kropek i kresek kwantowych. W drugiej części omówiono przykłady rezultatów dla studni I i II rodzaju przeznaczonych do zastosowań laserowych w czujnikach gazów (węglowodorów) na zakres 3...3,5 μm. W trzeciej części przedstawiono możliwości prowadzenia badań (spektroskopii modulacyjnej) w obszarze spektralnym powyżej 5 μm (interesującym np.: z punktu widzenia konstrukcji laserów kaskadowych) z zastosowaniem spektrometr Fouriera.
EN
We have shown the results of optical investigation realized in the Group of The Optical Spectroscopy of Nanostructures from Institute of Physics Wrocław University of Technology. The have been shown the advantages and possibilities which the modulation spectroscopy gives in case of investigation performed on Iow dimensional semiconductor structures (i.e. semiconductor lasers). The first port of the paper presents the results of optical investigations performed on quantum wells, dots and quantum dashes designed for telecommunication spectral range (1.3...1.55 μm). In the second part we have shown investigations of type I and II quantum well designed for laser structures in gas sensing application at (3...3.5 μm). In the last part, the opportunities of making modulation spectroscopy with and without Fourier spectrometer experiments above 5 μm spectral range have been discussed.
19
Content available remote A bicontinuous structure in some systems with cubic mesophases
63%
Yakunin A.
Open Physics
|
2004
|
tom 2
|
nr 3
535-555
EN
A cubic structure of polymer colloid complexes is studied. The technique of the research includes i) an analysis of well-known literature SAXS data; on this basis, ii) constructing a simple model to estimate geometric structure parameters and to obtain a simulated scattering curve; and iii) comparing the model with the real structure obtained from the SAXS data, using the reconstruction of electron density distribution. A bicontinuous structure in cubic mesophases is formed.
20
Mikrostruktura i odporność korozyjna natryskanych HVOLF nanostrukturalnych powłok WC12CO
63%
Żórawski W.
|
2010
|
tom Nr 3
6-10
PL
W pracy przedstawiono wyniki badań nanostrukturalnej powłoki WC12Co natryskanej naddźwiękowo (HVOLF). Nanostrukturalny proszek oraz natryskana powłoka były analizowane za pomocą mikroskopu skaningowego (SEM), mikroskopu transmisyjnego (TEM). Pokazały one, że ziarna proszku oraz natryskana powłoka zawierają nanokryształy WC. Natryskana nanostrukturalna powłoka charakteryzowała się większą gęstością w porównaniu z powłoką natryskaną z proszku konwencjonalnego. Badania odporności korozyjnej przeprowadzone przy użyciu zestawu Atlas’99 firmy Atlas-Sollich wykazały większą odporność korozyjną powłoki o budowie nanostrukturalnej.
EN
The paper presents results of investigations of nanostructured coating sprayed by means of hypersonic system (HVOLF). Nanostructured WC12Co powder feedstock and sprayed coatings were analysed by scanning electron microscope (SEM) and transmission electron microscope (TEM). Investigations revealed that grains of powder consisted of nanoparticles. Nanostructured sprayed coating possessed higher density in compare with coating sprayed with conventional powder applied. The corrosion tests carried out by means of device Atlas’99 (Atlas-Sollich) revealed that nanostructured coating possessed higher corrosion resistance.
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