Синтез тонких плівок оксиду титану методом розпилювального піролізу та його фотокаталітична активність для розкладання барвників та ципрофлоксацину

Titanium oxide (TiO2) thin film was obtained using the spray pyrolysis method. The structural properties of the thin film obtained were examined by X-ray diffraction (XRD) and it was found that it also had a tetragonal structure. The morphological feature was examined with scanning electron microscopy (SEM). In addition, the optical properties of the film were examined and the forbidden energy range was calculated. Photocatalytic properties of TiO2 thin film on dyestuff and antibiotic were investigated. Methyl blue and malachite green were used in the dye degradation test of the thin film. In particular, it was found to have a high degradation of 86% after 100 minutes on malachite green. Moreover, the degradation on ciprofloxacin after 90 minutes was found as 93%. The reusability ciprofloxacin antibiotic was investigated and it was found that synthesized TiO2 thin film has excellent stabilityТонкі плівки оксиду титану (TiO2) отримано методом розпилювального піролізу. Структурні властивості отриманих плівок досліджували за допомогою дифракції Х-променів (XRD) та встановлено наявність тетрагональної структури. Морфологічні особливості досліджували за допомогою скануючої електронної мікроскопії (SEM). Крім того, досліджено оптичні властивості плівки та розраховано ширину забороненої зони. Досліджено фотокаталітичні властивості тонкої плівки TiO2 на барвник та антибіотик. У тесті розкладання барвника тонкої плівки використано метиловий синій та малахітовий зелений. Зокрема, було виявлено високу деградацію 86% через 100 хвилин на малахітовому зеленому. Більше того, деградація ципрофлоксацину через 90 хвилин виявилася 93%. Досліджено антибіотик ципрофлоксацину та встановлено, що синтезована тонка плівка TiO2 має чудову стабільність

Дослідження впливу відпалу на питомий опір аморфних сплавів на основі алюмінію

In this study, electrical properties of Al-Y-Ni alloys produced by melt-spinning method were investigated. Before annealing, XRD analyzes were performed and the samples were found to be amorphous. Exothermic peaks were observed in DSC measurements and crystallization stages of the alloys were determined. Al85Y11Ni4, Al85Y10Ni5 and Al85Y5Ni10 samples were annealed at some temperature and their electrical resistivity was measured by four-point method. The large decrease in resistivity was observed during crystallization between 200 - 400 ˚C. These results were consistent with XRD and DSC measurements.У статті досліджено електричні властивості сплавів Al-Y-Ni, отриманих методом з розплаву. Перед відпалюванням проведено XRD-аналіз та виявлено аморфність зразків. При DSC-вимірюваннях спостерігалися екзотермічні піки та визначено стадії кристалізації сплавів. Зразки Al85Y11Ni4, Al85Y10Ni5 та Al85Y5Ni10відпалювали при певній температурі, а їх електричний опір вимірювали чотиризондовим методом. Під час кристалізації в інтервалі (200 - 400) °C спостерігається суттєве пониження питомого опору. Ці результати відповідали даним, отриманим із вимірюваннь XRD та DSC

Structural, mechanical and magnetic properties of Fe — 40-at.% Al powders during mechanical alloying

Nanocrystalline Fe — 40at.% Al alloy powders were prepared by using a mechanical alloying (MA) process with a planetary high-energy ball mill. The structural and the morphological properties of the powders were investigated by means of X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. A disordered Fe(Al) solid solution with bcc crystal structure was formed after 10 h of MA. Longer MA durations introduced ordering in the alloyed powders. The final crystallite size was found to be as small as 5 nm whereas the internal strain was found to reach a final value of 2.1%. Also, the lattice parameter quickly increased to a maximum value of 0.2926 nm at 30 h of MA, and then decreased to a value of 0.2873 at 80 h of MA. SEM results showed variations in the shapes and the sizes of the particles in the powders at different stages. Furthermore, the microhardness values were found to increase gradually with increasing MA time due to work hardening, grain refinement and solid-solution formation. Magnetic properties such as the saturation magnetization (Ms) and the coercive field (Hc) were calculated from the hysteresis loops, and the results are presented as functions of the MA time. © 2014, The Korean Physical Society

Boron and fluorine doped ZnO films obtained from zinc chloride precursor via chemical spray pyrolysis

Both boron (1, 2 and 3 at %) and fluorine (1, 3, 5 and 7 at %) doped zinc oxide thin films (ZnO:B:F) were fabricated using zinc chloride precursor by airbrush spray pyrolysis technique on glass substrates. X-ray diffraction (XRD) measurements show that all ZnO:B:F films have hexagonal wurtzite structure with a preferential growth along the [0 0 2] direction on glass substrates. Scanning electron microscope (SEM) results show that the morphologies of all doped films have a regular hexagonal shape. The optical measurements reveal that ZnO:B:F films have a direct band gap and optical energy gaps are increasing with boron and fluorine concentration. The optical transmittance of B and F doped ZnO films is measured very low due to columnar structure of prepared films. Moreover, it has been observed that the doping of ZnO films with boron and fluorine decreases the electrical resistance, and the lowest resistances of films were observed at 1%B–3%F and 2%B–3%F concentrations. © 2014, Pleiades Publishing, Ltd

Structural and physical properties of boron doped ZnO films prepared by chemical spray pyrolysis method

In this work, ZnO and boron doped ZnO (ZnO:B) thin films were produced by chemical spray pyrolysis method. ZnO and ZnO:B films were obtained onto glass substrates at 450°C by spray pyrolysis method and the physical properties of those films were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectrometer (UV) and four probe technique. XRD measurements show that all films have hexagonal wurtzite structure and all films grow preferentially along (002) direction. Morphologies of the films were examined by using a scanning electron microscopy and it was observed that almost all films were quite intense with a regular structure. Optical measurements showed that the band gap energies of the films increased with boron concentrations. The resistances of the B-doped ZnO films were measured by four probe method and resistances of films initially decreased to its minimum 1 at% boron doping and then it increased again with increasing B concentration. It was also observed that that boron doping increased the activation energies of the films. © 2015, Pleiades Publishing, Inc

Examination of the change of the characteristic X-rays of the zinc in fluorine- and boron-doped ZnO thin films

In this study, K_{β}/K_{α} X-ray intensity ratios of zinc in pure zinc, undoped ZnO thin film and boron and fluorine-doped ZnO thin films have been investigated. These samples have been excited by 59.5 keV γ-rays from a ^{241}Am annular radioactive source. K X-rays emitted by the samples have been counted using an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The K_{β}/K_{α} X-ray intensity ratios of the doped ZnO thin films have been compared with that of the undoped ZnO thin film. The deviations between the results can be explained by delocalization and/or charge transfer phenomena causing change in valence electronic configuration of zinc

Microstructural investigations of rapidly solidified al-co-y alloys

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al 85Co7Y8 alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co 13Y2 and Al85Co2Y13 alloy ribbons were fully crystalline, whereas Al85Co10Y 5 and Al85Co5Y10 alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al 85Co7Y8 amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (?Tx=Tx-Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed. © 2013 B. Avar et al

Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8 alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2 and Al85Co2Y13 alloy ribbons were fully crystalline, whereas Al85Co10Y5 and Al85Co5Y10 alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8 amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed