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EN
This paper presents results of X2CrNiMoN25-7-4 steel structure investigation. Measurements were carried out in commercial state and after additional solution heat treatment. The structure analysis was carried out based on XRD measurements. Obtained results allowed for determination of structure parameters, phase's volume and lattice defects. Obtained results suggested, that applied finishing treatments didn't influent on structure parameters and the lattice defects.
PL
W pracy przedstawiono wyniki badań struktury stali X2CrNiMoN25-7-4. Badania przeprowadzono dla stanu komercyjnego materiału oraz po procesie powtórnego przesycania. Strukturę materiału analizowano na podstawie pomiarów dyfraktometrycznych. Określono parametry sieciowe składników, stopień zdefektowania struktury oraz wyznaczono udziały fazowe. Analiza wyników badań wykazała, że stosowane na etapie produkcji zabiegi wykańczające nie wpłynęły na parametry strukturalne oraz stopień zdefektowania struktury.
PL
Hydroksyapatyt (HAp), jedna z odmian fosforanów wapnia, stanowi główny składnik kości i zębów. Tworzy ich mineralną macierz i nadaje im sztywność. Należy do grupy najlepszych biomateriałów. Syntetycznie wytwarzany HAp ma jednak wady, takie jak: kruchość, słaba adhezja do podłoża, mała wytrzymałość mechaniczna i mały stopień krystaliczności. Wady te w znacznym stopniu ograniczają jego zastosowanie. Celem badań było określenie wpływu modyfikacji za pomocą obróbki termicznej i hydrotermalnej cienkich powłok hydroksyapatytu nałożonych na stop tytanu Ti6Al7Nb oraz na stopu tytanu z warstwą węglową Ti6Al7Nb/C. Przeprowadzono również wygrzewanie hydrotermalne samego proszku HAp w celu sprawdzenia wzrostu krystalitów. Zadaniem obróbki termicznej i hydrotermalnej jest głównie zwiększenie stopnia krystaliczności, dzięki czemu poprawiają się właściwości mechaniczne, chemiczne oraz biologiczne HAp. Do badań przygotowano dwa rodzaje próbek na podłożu metalicznym w układach Ti6Al7Nb/HAp oraz Ti6Al7Nb/C/HAp, które poddano wygrzewaniu w piecu, w środowisku suchym, w atmosferze azotu oraz wygrzewaniu hydrotermalnemu w autoklawie. Wygrzewanie hydrotermalne uzależniono od parametrów, takich jak czas ekspozycji oraz pH wody. W badaniach wygrzewano również hydrotermalnie proszek hydroksyapatytowy, uzależniając proces wygrzewania od czasu ekspozycji w autoklawie. Wygrzewanie w piecu pomimo licznych doniesień literaturowych nie przyniosło oczekiwanych efektów. Naniesione powłoki uległy w dużej części zniszczeniu, a podłoże utleniło się. Przyczyną mogła być zbyt mała ich grubość oraz niedostateczna adhezja. Obiecujące wyniki przyniosło Wygrzewanie hydrotermalne. Niezależnie od środowiska wygrzewania (zasadowe, kwaśne) hydroksyapatytowe powłoki zwiększyły stopień krystaliczności. Jednocześnie ze wzrostem struktur krystalicznych następowało stopniowe odkrywanie podłoża. Jest to związane z pobieraniem materiału do krystalizacji z najbliższego otoczenia. Poddane obróbce hydrotermalnej proszki HAp zostały zbadane metodą XRD. Badanie wykazało wzrost wielkości krystalitów oraz zwiększenie ilości fazy krystalicznej.
EN
The subject of the present work is hydroxyapatite (HAp), a material constituting the main component of bones and teeth, forming their mineral matrix and determining their rigidity. A member of the calcium phosphate family, the compound is one of the best biomaterials. However, synthetic brands of HAp are characterized by a number of setbacks such as: brittleness, poor adhesion, low mechanical strength, and low degree of crystallinity, which severely restrict their applications. The aim of the study was to investigate the effect of thermal and hydrothermal annealing of thin hydroxyapatite films deposited on titanium alloy Ti6Al7Nb and on carbon coated titanium alloy Ti6Al7Nb/C. In addition, hydrothermal annealing of HAp powder was also carried out in order to com- pare different conditions of a growth of crystalline phase. Both thermal and hydrothermal annealing processes are cited in the literature as methods of improving the above mentioned HAp properties by means of increasing its degree of crystallinity. Two types of samples, namely those of Ti6Al7Nb/HAp and Ti6Al7Nb/C/ HAp geometry, were subj ected to both dry thermal annealing at 870°C in an oven and hydrothermal annealing at 134°C in an autoclave. Hydrothermal annealing was carried out using exposure time and water pH as operational process parameters. Autoclave exposure time was also used as a parameter in the case of hydrothermal annealing of hydroxyapatite powder. Thermal annealing in the oven did not produce expected results. The coatings were destroyed and the substrates oxidized. Much more promising results were obtained in the case of hydrothermal processing. Independent of the environment (either basic or acidic), the HAp material underwent crystallization. However, the larger was the crystallite size, the more fraction of a substrate remained uncoated. Evidently, material for the crystallization was collected from the crystallite direct neighborhood.
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Content available remote Crystallization of 45S5 during isothermal heat treatment
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EN
Bioglass 45S5 has been shown inter alia to enhance bone growth, making it an interesting material for implants and scaffolds. Scaffolds are sintered from powdered glasses, and are partially crystalline. Crystallization of powdered 45S5 is well reported in the literature. 45S5 easily crystallizes also during hot-working to various implants. Crystallization of 45S5 plates at isothermal treatments was studied systematically for up to six hours at ten different temperatures (600-1000°C). The samples were inserted into a preheated furnace, and after the treatment the samples were rapidly cooled in the nitrogen flow. XRD, SEM, and optical microscope were used to identify the phase changes. According to the optical microscope images, the phase separation commenced around 600°C. The phase separated regions became more apparent at 700°C, and above 800°C a uniform crystal structure was observed. According to SEM, the crystal aggregates in the bulk showed truncated cube-like morphology (10-40 žm). At higher temperatures two different crystal structures could be identified on the surface. The X-ray diffraction pattern evolution was followed as the functions of time and temperature. The first peaks were observed at 650°C and the best match was obtained with Na2CaSi2O6. An evident broadening of the main peak (at 20 ≈ 34°), leading to a separation into two peaks, was observed around 700°C; the separation of the peaks increased linearly as the function of temperature. On plate surfaces the crystallization was similar to the reported results with powdered samples, while in the cross-sectional surface only one crystalline phase was observed.
PL
W przypadku bioszkła 45S5 inter alia pokazano, że sprzyja wzrostowi kości, co czyni go interesującym materiałem na wszczepy i rusztowania. Rusztowania spieka się ze sproszkowanego szkła i są one częściowo krystaliczne. Krystalizacja sproszkowanego szkła 45S5 jest dobrze opisana w literaturze. Szkło 45S5 łatwo krystalizuje również podczas obróbki na gorąco prowadzącej do wykonania różnych wszczepów. Krystalizację płytek ze szkła 45S5 podczas izotermicznej obróbki badano systematycznie aż do sześciu godzin w dziesięciu różnych temperaturach (600-1000°C). Próbki umieszczano we wcześniej nagrzanym piecu, a po obróbce, próbki szybko schładzano w strumieniu azotu. Metody XRD, SEM i mikroskopii optycznej wykorzystano do zidentyfikowania zmian fazowych. Zgodnie z obrazami mikroskopii optycznej, rozdzielenie fazowe rozpoczęło się w około 600°C. Obszary rozdzielenia faz stały się bardziej widoczne w 700°C, zaś powyżej 800°C zaobserwowano jednorodną strukturę krystaliczną. Zgodnie z obserwacjami SEM, agregaty krystaliczne w objętości materiału pokazały morfologię podobną do ściętego sześcianu (10-40 žm). W wyższych temperaturach dwie różniące się struktury krystaliczne można było zidentyfikować na powierzchni. Ewolucja dyfraktogramów rentgenowskich śledzona była w funkcji czasu i temperatury. Pierwsze piki zaobserwowano w 650°C i najlepsze dopasowanie uzyskano dla Na2CaSi2O6. Widoczne poszerzenie głównego piku (przy 20 ≈ 34°), prowadzące do rozdzielenia na dwa piki, zaobserwowano w 700°C; rozdzielenie pików zwiększało się liniowo w funkcji temperatury. Na powierzchniach płytkowych krystalizacja przebiegała podobnie do opisanej w próbkach proszkowych, podczas gdy na powierzchni przekroju zaobserwowano tylko jedną fazę krystaliczną.
PL
Praca zawiera wyniki badań dotyczących rentgenowskiej analizy dyfrakcyjnej XRD (badanie składu fazowego, wielkości krystalitów) warstw tlenkowych na stali 13CrMo4-5 długotrwale eksploatowanej w podwyższonej temperaturze (T = 525°C, t = 73 000 h). Badania rentgenograficzne przeprowadzono na powierzchni zewnętrznej rury, następnie powierzchnię warstwy polerowano i ponownie wykonywano pomiary dyfrakcyjne w celu określenia poszczególnych warstw tlenkowych. Próbki poddano pomiarom rentgenowskim z użyciem dyfraktometru rentgenowskiego Seifert 3003T/T i promieniowania pochodzącego z lampy o anodzie kobaltowej (λCo = 0,17902 nm). Wykonano badania rentgenowskie obejmujące pomiary w symetrycznej geometrii Bragga-Brentano (XRD). Pomiary XRD wykonano w zakresie kątów 30÷120°, z krokiem kątowym 0,1° i czasem ekspozycji 4 s. W celu interpretacji wyników (wyznaczenia położenia 2θ) dyfraktogramy opisano krzywą Pseudo Voighta z użyciem programu Analyze. W identyfikacji faz wykorzystano program komputerowy i bazę danych krystalograficznych DHN PDS oraz PDF4+2009. Na podstawie szerokości i położenia refleksów głównych warstwy tlenkowej wyznaczono wielkość krystalitów ze wzoru Scherrera.
EN
The paper contains results of the studies on X-ray diffraction analysis XRD (studying the phase composition, crystallite sizes) of oxide layers on 13CrMo4-5 steel, operated for a long time at elevated temperature (T = 525°C, t = 73,000 h). X-ray studies were carried out on the outer surface of a tube, and then the layer surface was polished down and the diffraction measurements were performed again to determine individual oxide layers. X-ray (XRD) measurements were performed on a Seiffert 3003T/T X-ray spectrometer with a cobalt target tube (λCo = 0.17902 nm). X-ray studies were performed, comprising measurements in a symmetric Bragg- Brentano geometry. XRD measurements were performed in the 30÷120° range of angles with an angular step of 0.1° and the exposure time of 4 s. To interpret the results (to determine the 2θ position and the total intensity INet) the diffraction paterns were described by a Pseudo Voight curve using the Analyze software. A computer software and the PDF4+2009 crystallographic database were used for the phase identification. Based on the width and location of the main oxide layer reflections, the crystallite size has been determined from the Scherrer formula.
EN
In this study, the irreversible expansion of TATB cylinder is investigated. No evident variation of the lattice parameters is observed on TATB crystal. The density of TATB powder decreases by only about 0.02% after it suffered from thermal cycling process at the range from -54 C to 74 C, while the density of TATB cylinder decreases by about 1.0%. It is suggested that the density variation of TATB powder has little contribution to the density decrease of TATB cylinder. Therefore, the increasing interstices between TATB powder originated from the thermal cycling should be responsible to the irreversible expansion of TATB cylinder.
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EN
The 0.5(BiGd0.05Fe0.95O3)-0.5(PbZrO3) composite was synthesized by means of a high temperature solid-state reaction technique using high purity ingredients. Preliminary X-ray structural analysis confirms the formation of the composite. The dielectric constant and loss tangent have been studied. The impedance parameters have been measured using an impedance analyzer in a wide range of frequency (102–106 Hz) at different temperatures. The Nyquist plot suggests the contribution of bulk effect only and the bulk resistance decreases with a rise in temperature. Electrical impedance confirms the presence of grain effect and hopping mechanism in the electrical transport of the material. The dc conductivity increases with a rise of temperature. The frequency variation of ac conductivity shows that the compound obeys Jonscher’s universal power law and from Jonscher’s power law fit confirms the Small Polaron (SP) tunneling effect. Temperature dependence of dc and ac conductivity indicates that electrical conduction in the material is a thermally activated process.
EN
The aim of the present paper was to investigate microstructure and texture evolution of two single crystals and polycrystal of Cu-8.5%at.Al material. All of mentioned samples were deformed by HE to achieve true strain ε = 1.17. For microstructure analyzes observations by transmission electron microscope (STEM) were done. Crystalline size for samples after SPD were determine using XRD method. The global texture measurements were done using Bruker D8 Discover diffractometer equipped in Cr radiation. Microstructure investigations revealed nanocrystalline structure in single crystals with initial orientations <110> and <100> and polycrystalline Cu-8.5%at.Al material after SPD. The global texture measurements have shown the stability of initial orientation of <100> Cu-8.5%at.Al single crystal after HE, whereas the same SPD process strongly brakes up the orientation <110> Cu-8.5%at. Al single crystal.
EN
Nanoneedle structured Sn2S3 thin films were prepared by spray pyrolysis technique from aqueous solutions of tin (II) chloride and thiourea, keeping the molar concentrations of S:Sn = 0.01:0.01, 0.02:0.02, 0.03:0.03 and 0.04:0.04 in the starting solutions. XRD studies reveal that all the films exhibit orthorhombic crystal structure with a preferential orientation along the [2 1 1] direction. The peak intensity of the (2 1 1) plane is found to be maximum for the film coated with 0.02:0.02 S:Sn molar concentration which confirms the improved crystalline nature of this film. SEM images depict that the film coated with S:Sn molar concentration 0.02:0.02 exhibit needle shaped grains. The optical band gap exhibits red shift from 2.12 eV to 2.02 eV with an increase in S:Sn precursor molar concentration. Electrical studies show that the films having S:Sn molar concentrations 0.01:0.01 and 0.02:0.02 exhibit minimum resistivity values of 0.238 and 0.359Ω ·cm, respectively.
EN
Manganese sulphide (MnS) thin films were prepared by chemical bath deposition method. X-ray diffraction analysis was used to study the structure and the crystallite size of MnS thin films. The grain size and the surface morphology were studied using scanning electron microscopy. The optical properties were studied using the UV-visible absorption spectrum. The dielectric properties of MnS thin films were studied for different frequencies and different temperatures. Further, electronic properties, such as valence electron plasma energy, average energy gap or the Penn gap, the Fermi energy and electronic polarizability of the MnS thin films were calculated. The ac electrical conductivity study revealed that the conduction depended both on the frequency and the temperature. The temperature dependent conductivity study confirmed the semiconducting nature of the films.
EN
Nanocrystalline CdS thin films were successfully prepared using simple chemical bath deposition technique. Cadmium sulphate, thiourea and deionised water were used as starting precursor solution. The prepared thin films were characterized using X-ray diffractogram (XRD), Scanning electron microscope (SEM), elemental composition using energy dispersive spectrophotometer (EDAX) and optical band gap (UV-Spectroscopy).X-ray diffractogram reveals that present of cubic and hexagonal phase. The thickness, crystallite size and grain size were observed to be increase with increase operating temperature of bath while optical band gap energy slightly decreases. Effect of deposition temperature on physical, structural, microstructural, electrical and optical properties of these films was studied and presented in the present investigation. Prepared thin films shows good response towards photoconducting in presence and absent of light.
EN
Polycrystalline Cadmium sulfide (CdS) films were deposited onto Corning glass substrates from alkaline solutions containing CdCl2, KOH, Na3C6H5O7 and CS(NH2)2 at different deposition times (10, 20, 30, 40 and 50 min), different bath temperatures and different concentration of the reactants. A comparative study was performed out on thin film via optical transmission and X-ray diffraction (XRD) measurements which reveal that the deposition time has a profound influence on the growth rate and band gap of the deposited layers. Diffraction data are used to evaluate the lattice parameter, grain size, average strain, number of crystallites per unit area and dislocation density in the film are calculated.
EN
This paper presents the application of X-ray fluorescence and X-ray diffraction methods for the study of copper oxide structures as an absorber layer in thin-film solar cells. The layers of copper oxide were applied by direct current magnetron sputtering. Quantitative and qualitative analysis of oxide layers were performed using XRF (X-ray fluorescence). The studies showed a high copper content in both samples, amounting to 98% and 96%, as well as trace amounts of other elements (nickel, lead). The XRD (X-ray diffraction) study showed Cu20 and Cu8O phases, amorphism ranging from 24% to 44%, and crystallinity from 55% to 75%. Crystallites of 30 nm were also determined. The aim of the study was to determine the chemical and phase composition of the layers obtained and to determine the degree of their contamination depending on the parameters of the manufacturing technology in terms of their application in photovoltaics. One of the samples showed an advantage both in terms of material and structural composition.
EN
Present paper reports optical and electrical properties of samarium doped CdSe nanocrystalline thin film which was grown on a glass substrate by chemical bath deposition method (CBD). X-ray diffraction (XRD) analysis revealed that the deposited films were nanocrystalline with sphalerite cubic structure. The average crystallite size calculated from FWHM of XRD peaks was found to be 10.11 nm. The bandgap of the Sm doped CdSe nanocrystalline thin films was calculated to be 1.91 eV to 2.22 eV. The optical absorption edge of undoped (pure) and Sm doped CdSe films was obtained between 650 nm to 640 nm showing blue shift as compared to bulk CdSe. Sm doping further enhanced the photoconductivity of these films. The I-V characteristic confirmed the suitability of prepared films for photosensor applications.
EN
In the ternary system MgO-Na2O-P2O5 the binary system Mg3(PO4)2-Na3PO4 was investigated by thermal analysis, X-ray and microscopy, and its phase diagram was proposed. Three intermediate compounds occur in this system with the molar ratio Mg3(PO4)2-Na3PO4 4:1, 1:1 and 1:4, and corresponding formulas Mg4Na(PO4)3, MgNa-PO4 and MgNa4(PO4)2. The phosphate Mg4Na(PO4)3 melts incongruently at 11550C, the MgNa4(PO4)2 melts incongruently at 16550C, whereas the phosphate MgNaPO4 occurs only in the solid phase, which undergoes decomposition at 950-9600C. The polymorphism of these phosphates was investigated and temperatures of polymorphic transitions were determined.
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We report on ZnO films doped with different Co concentrations (0, 0.5, and 1 wt%) prepared by sol-gel technique in association with dip-coating onto glass substrates. Zinc acetate dehydrate, cobalt acetate, mono ethanolamine were used as starting materials, as well as solvent and stabilizer, respectively. Nanostructured polycrystalline ZnO thin films with different concentrations of Co doping (0, 0.5, and 1 wt%) are prepared for the first time by the sol-gel method and annealed at 500°C for 1 h. The surface morphologies of the ZnO thin films deposited on glass substrate with different concentrations were evaluated by atomic force microscopy. The optical absorption of the films showed a blue shift of the band gap. The photoluminescence signal of the thin films of undoped and Co-doped ZnO presents different bands in the visible region. The electrical conductivity of the sample with 0.5%Co was found to be 4.62 (ΩCm)¯¹.
EN
In this paper, Cd0.3Zn0.7S thin film has been electrodeposited from aqueous bath containing CdSO4, ZnSO4, Na2S2O3 and EDTA, having pH ~ 14. The structural, optical, morphological, surface wettability and photoluminescence properties of the film were investigated. The XRD pattern showed that the film consisted of mixed phases of CdS and ZnS with polycrystalline structure. The bandgap of the film was evaluated as 2.69 eV. The AFM study revealed that the Cd0.3Zn0.7S thin film contained spherical grains with root mean square roughness of 6.09 nm. The water contact angle measurement showed that the thin film was hydrophilic in nature. Moreover, the PL study revealed that the excitation wavelength was 460 nm.
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Content available remote Surface properties in titanium with hydroxyapatite coating
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EN
Due to its wide range of possible applications in current technology, hydroxyapatite, as a biomaterial, has been of great interest to scholars. Improvement in mechanical properties can be achieved by addition of zirconia, partially stabilized by yttrium, into a resistant oxide phase. The present study describes the microstructure and phases which are typical of composite coatings after plasma spraying.
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Content available remote A novel technique for the synthesis of CaCu3Ti4O12 ceramics
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EN
A novel, low temperature synthesis technique is developed for fabrication of nanocrystalline CaCu3Ti4O12 ceramic powders, using inexpensive and easily available reagents. Structural and microstructural characterization was undertaken by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The confirmation regarding the phase formation was done using the Reitveld analysis. The compound belongs to the cubic system with the lattice parameter a = 7.3985 A, which agrees well with the values reported in the literature. The particles formed were spherical in shape, with the average size of 70 nm.
EN
Here, we report the unusual behavior shown by the PbS samples prepared using a multilayer deposition approach by chemical solution deposition method. Thin samples were prepared by depositing several films at different deposition conditions on glass substrates. X-ray diffraction showed that final multilayer samples showed a peculiar variation. Even when they showed well defined structure the intensities of the peaks do not correspond to those of the initial films.
EN
Polycrystalline Cadmium sulfide (CdS) films were deposited onto Corning glass substrates from alkaline solutions containing CdCl2, KOH, Na3C6H5O7 and CS(NH2)2 at different deposition times (10, 20, 30, 40 and 50 min), bath temperatures (80 ±2 °C) and different concentration of the reactants. A comparative study was performed out on thin film via optical transmission and X-ray diffraction (XRD) measurements. The results which reveal that the deposition time has a profound influence on the growth rate and band gap of the deposited layers. Diffraction data was used to evaluate the lattice parameter, grain size, average strain, number of crystallites per unit area and dislocation density in the film are calculated.
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