Growth and characterization of ZnMnO thin films

Zn1−xMnxO (0 ≤ x ≤ 0.1) thin films were grown on sapphire substrates by pulsed laser deposition and rf magnetron sputtering methods. As a target source ceramic pellets prepared by mixing ZnO and Mn3O4 powders were used. The shift of the absorption edge due to increase the energy band gap with increasing Mn content was observed in optical absorption spectra of the Zn1−xMnxO thin films. Magnetic susceptibility and magneto-optical Faraday rotation experiments show paramagnetic behavior and absence of ferromagnetic ordering in the studied films.This work has been supported in part by grant No. M/128-2004 from the Ministry of Education and Science of the Ukraine

Semimagnetic semiconductor oxides as materials for transparent electronics and spintronics

Zinc oxide-based semimagnetic semiconductor (SMS) ZnMnO, ZnMnFeO and ZnMnSnO thin films were deposited on sapphire and glass substrate by pulsed laser deposition (PLD) and RF sputtering techniques. Further, ZnMnO nanocrystals embedded in polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) matrices were prepared by chemical method employing zinc acetate and manganese acetate as precursors. The morphology of the thin films was studied using atomic force microscopy (AFM). Large variety of the morphology images was obtained depending on the film composition and growth conditions. The most interesting feature was observed for the ZnMnSnO films, in which the formation of clusters including nanowire-like structures was shown. Optical transmission spectra suggest that metalsMn, Fe and Sn substitute for Zn2+ ions in the ZnO lattice, resulting in the increase in the band gap energy.Magneto-optical Faraday rotation measurements confirm ferromagnetic ordering in ZnMnFeO thin films and paramagnetic behaviour for the other films.The work has been supported in part by the Ministry of Education and Science of Ukrain

Formation and transformation of II-VI semiconductor nanoparticles by laser radiation

Pulsed laser deposition has been applied for fabrication of Cd1-xMnxTe nanocrystals embedded in SiO2 matrix. By further thermal annealing an increase of average size of nanoparticles and narrowing of their size distribution was reached. Colloidal chemistry methods were used for preparing of Cd1-xMnxS nanoparticles. After UV irradiation of the colloidal solution with Cd1-xMnxS nanoparticles the average size and size distribution was changed owing size-selective photoetching mechanism. Results of optical and magneto-optical characterizations of the as-grown and the treated nanoparticle samples are described.The work was partially supported by the Ministry of Education and Science of Ukrain

Biosensors for Cellular Imaging on the Base of Colloidal CdMnS Nanoparticles

Semiconductor nanoparticles have rapidly found a broad range of applications as optical imaging agents. The presented paper describes the growth, analysis of optical spectra and study of cellular imaging of Mn-doped cadmium sulfide nanoparticles. Semimagnetic semiconductor nanoparticles CdMnS are characterized by high brightness, improved photostability and multicolor size- and structure-dependent light emission in the visible range of spectra. They are emerging as a new class of fluorescent reporters with properties and applications that are not available with traditional organic dyes. In order to obtain nanosensors different surfactants, growth factors and conditions such as surfactant concentrations, ionic strength, precursor concentration have been varied. Formation of nanoparticles was monitored by optical methods. The average nanoparticle size was estimated by optical spectra. For cellular research histological section of a placental tissues and liver tissues has been used. This procedure is possible only after cell fixation and permeabilization treatment is needed to allow the nanosensors to enter inside the cell

Effects of codoping in ZnO-based semimagnetic semiconductor thin films

Single doped Zn1-xMnxO, Zn1-xFexO and codoped Zn1-x-yMnxFeyO, Zn1-x-yMnxSnyO, Zn1-x-yMnxLiyO, Zn1-x-yFexAlyO thin films were grown on sapphire and glass substrate by pulsed laser deposition and RF sputtering techniques. No secondary phases was detected from XRD analysis. Among the studied oxide films single doped with Fe and codoped with (Mn,Fe) and (Fe, Al) exhibit n-type conductivity and room temperature ferromagnetic behaviour. For the films codoped with (Mn, Sn) formation of clusters including nanowire-like structures was shown from AFM analysis. Optical and magnetooptical studies suggest of Mn, Fe, Sn and Li substitution for Zn2+ ions in ZnO lattice.This research was partially supported by the Ministry of Education and Science of Ukraine

Evolution of CdS:Mn nanoparticle properties caused by pH of colloid solution and ultrasound irradiation

The effects of pH value and precursors concentrations in the growth solution as well as of ultrasound irradiation on the properties of CdS:Mn nanoparticles in PVA matrix are studied. Analysis of the photoluminescence spectra indicates that the increase of the pH value in the growth solution leads to the increase of the density of surface electron states that participate in radiative transitions and to the enlargement of CdS:Mn nanoparticles.We discuss a stabilization of the sizes of CdS:Mn nanoparticles at pH=6 and change of nanoparticle size with decreasing pH value at elevated concentrations of ions HS- . It is shown that in the ultrasound-treated samples the size of the particles does not depend on pH value. The effects of ultrasound result primarily from acoustic cavitation. It is demonstrated that the action of two external factors (the value of the medium pH and ultrasound treatment) on the characteristics of nanoparticles is correlated

Влияние момента инерции на мощность и жесткость при токарной обработке детали

Was made the analysis of influencing of moment of inertia on power necessary for treatment of detail trunnion, on the stage of lathe treatment, in this work. Was made the analysis of influencing of moment of inertia on oscillation processes, that happened in the area of treatment of detail, defined the frequency of own oscillations of detail which causes resonance and amplitude of its oscillations, influencing on inflexibility of the processed detail.В работе проведен анализ влияния момента инерции на мощность, необходимую для обработки крестовины на стадии токарной обработки. Выполнен анализ влияния момента инерции на колебательные процессы, происходящие в зоне обработки детали, определена частота собственных колебаний детали, при которой возникают резонанс и амплитуда ее колебаний, влияющих на жесткость обрабатываемой детали. // Укр. версія: У роботі проведений аналіз впливу моменту інерції на потужність, необхідну для обробки хрестовини на стадії токарної обробки. Виконаний аналіз впливу моменту інерції на коливальні процеси, що відбуваються в зоні обробки деталі, визначена частота власних коливань деталі, при якій виникають резонанс і амплітуда її коливань, що впливають на жорсткість оброблюваної деталі. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/70