Polyester and Polyesterimide Compounds with Nanofillers for Impregnating of Electrical Motors

Polyester and polyesterimide compounds for impregnating of electrical motors were modified by incorporating of three kinds of nanofillers: zinc oxide, fumed nanosilica and titanium dioxide so as to improve their properties. Nanosized particles were added at 1 wt.% of loading and homogeneously dispersed in polyester and polyesterimide matrix. The results on mechanical, electrical and barrier properties of standard and nanofilled compounds were compared. Thermogravimetric/differential thermal analysis showed that thermal stability of nanofilled compounds was significantly higher. Also the electrical and bonding strength of nanofilled impregnating compounds increased and at the same time water absorption decreased. The highest improvement of properties owing to nanofillers was obtained in the case of nanosilica

Study of Structure Densification in TiO2TiO_2 Coatings Prepared by Magnetron Sputtering under Low Pressure of Oxygen Plasma Discharge

Current work presents results of studies on structural and optical properties of the $TiO_2$ thin films prepared by reactive magnetron sputtering. Oxide thin films were deposited from metallic targets using oxygen gas only instead of usually used mixture of Ar-$O_2$. Additionally, an increased amplitude of unipolar pulses powering the magnetron has been applied. It is shown that all prepared coatings were stoichiometric and by changing only the discharge voltage it is possible to influence the resulting structural phase and optical properties of prepared thin films. Depending on conditions of magnetron powering, $TiO_2$ thin films had either the anatase structure with refraction index n = 2.1 (λ = 500 nm) or a high temperature stable rutile structure with n = 2.52 (λ = 500 nm)

Characterization of Transparent and Nanocrystalline TiO2:NdTiO_{2}:Nd Thin Films Prepared by Magnetron Sputtering

In this work structural and optical properties of $TiO_{2}$ thin films doped with different amount of Nd have been outlined. The result have shown that by quantity of Nd amount in the film dense nanocrystalline or amorphous thin films were obtained

Antistatic Properties of Nanofilled Coatings

The results of antistatic and electrical properties investigations of nanofilled coatings have been presented. Antistatic performance of materials is essential not only due to safety and preventing of dust and dirt attraction but also effects on an electrical field distribution in the high voltage insulating systems. The polymer coating added with silver and silica nanoparticles were examined by charge decay measurements after corona charging. The charge decay times have varied appreciably between the nanofilled coatings while the volume and surface resistivity of the all tested coatings did not demonstrate meaningful differences. The polyester coating dissipated fairly better than polyesterimide because of its structure and permittivity. It was found that the ability of surface to drain charge away is the better for coatings with of silver nanoparticles whereas the coatings modified with nanosilica shows the poor antistatic properties; the times of charge decay were four order longer then that of unmodified coatings. Barrier properties of nanosilica may be adverse for charge decay

Thin Films Based on Nanocrystalline TiO2TiO_{2} for Transparent Electronics

In this work, investigations of structural, optical and electrical properties of transparent oxide semiconductor thin films based on $TiO_{2}$ doped with Eu, Pd and Tb, Pd have been presented. The transparent oxide semiconductor nanocrystalline thin films were prepared by magnetron sputtering process. It was shown that doping with selected elements results in semiconducting properties of prepared thin films of oxides with p-($TiO_{2}$:(Tb, Pd)) or n-type ($TiO_{2}$:(Eu, Pd)) of electrical conduction

Badanie właściwości elektrycznych cienkich warstw TiO2 domieszkowanych Eu I Pd naniesionych na podłoża krzemowe

In this work, investigations of electrical properties of Eu and Pd-doped TiO2 thin films have been outlined. Our previous studies [4, 6] of Eu and Pd-doped TiO2, have shown the nanocrystalline structure and high transparency in visible region (about 70%). Now, it has been shown that by incorporation of Pd and Eu dopants into TiO2 matrix, its properties can be modified so as to obtain simultaneously electrically and optically active oxide-semiconductor with specified type of electrical conduction at room temperature. Pd dopant changes the electrical properties of TiO2 from dielectric oxide to conducting oxide. Samples were examined by means of theromelectrical, current-voltage (I-V), transient photovoltage and optical beam induced current OBIC (Optical Beam Induced Current). I-V measurements showed formation of electrical junctions at the interface of semiconducting thin films of metal oxides and silicon substrate (TOS-Si). The presence of build-in potential has been confirmed by OBIC through created maps of photocurrent distribution generated in the active areas of prepared TOS-Si heterojunctions.W niniejszej pracy przedstawiono badanie właściwości elektrycznych cienkich warstw TiO2 domieszkowanych Eu i Pd. Pokazano, że wprowadzenie domieszki Eu i Pd do matrycy TiO2 modyfikuje jej właściwości, pozwala otrzymać cienkie warstwy elektrycznie i optycznie aktywne. Dodatkowo, wytworzone tlenki posiadają określony typ przewodnictwa elektrycznego w temperaturze pokojowej. Decydujący wpływ na właściwości elektryczne matrycy TiO2 miała domieszka Pd, która umożliwiła zmianę właściwości cienkich warstw dielektrycznych na półprzewodnikowe. Próbki badano za pomocą charakterystyk termoelektrycznych, charakterystyk prądowo-napięciowych (I-V) oraz metodą OBIC. Na podstawie pomiarów I-V zaobserwowano formowanie się złącza na granicy przezroczysty tlenek półprzewodnikowy-podłoże krzemowe (TOS-Si). Mapy rozkładu fotoprądu generowanego w obszarach aktywnych wytworzonego heterozłącza TOS-Si potwierdziły obecność potencjału wbudowanego

Electrical and optical study of transparent V-based oxide semiconductors prepared by magnetron sputtering under different conditions

This work is focused on structural, optical and electrical behaviors of vanadium-based oxide thin films prepared by magnetron sputtering under different conditions. Thin films have been deposited on glass substrates from metallic vanadium target at low sputtering pressure. Different working gases: argon/oxygen mixture, and especially pure oxygen gas, have been applied. Results of X-ray diffraction together with optical transmission and temperature- dependent electrical resistivity measurements have been presented. Transmission coefficient, cut-off wavelength and the width of the optical band gap have been calculated from optical measurements. The d.c. resistivity values at room temperature and thermal activation energy have been obtained from electrical investigations. The influence of sputtering process conditions on optical and electrical properties has been discussed

Properties of Nanocrystalline TiO2:VTiO_{2}:V Thin Films as a Transparent Semiconducting Oxides

In this work the nanocrystalline $TiO_{2}$ thin films doped with vanadium in amount of 19 at.% and 23 at.% prepared by magnetron sputtering method have been presented. The transmission measurements shows that V-doped $TiO_{2}$ thin films were transparent in ca. 81% in the visible range of light spectrum. On the basis of electrical examinations it was found that fabricated $TiO_2:V$ thin films are semiconductors at room temperature and have different type of electrical conduction depending on the amount of vanadium dopant applied

Badanie właściwości strukturalnych i optycznych cienkich warstw TiO2:(Eu, Pd) wytwarzanych metodą rozpylania magnetronowego

In this study the results on TiO2 thin films doped with europium and palladium at the amount of 0.9 at. % and 5.8 at. % respectively have been presented. For thin films deposition the high energy (HE) magnetron sputtering method was used. Some samples were subjected to the post-processed annealing. X-Ray Diffraction (XRD) results have shown that after deposition nanocrystalline TiO2 - rutile structure was obtained. After additional annealing at 800°C average crystallites sizes increased about twofold (from 9 to 16 nm). The XRD results were confirmed using atomic force microscope. Optical properties of thin films were examined using optical transmission method. They have shown that doping with Eu and Pd has decreased the transmission level by about 15% and shifted absorption edge to the longer wavelength range (from 330 to 450 nm) compared to pure TiO2. The width of optical bandgap of TiO2:(Eu, Pd) thin film decreased to ca. 1.7 eV, i.e. twofold, when compared to 3.35 eV of undoped-TiO2. The photoluminescence results have shown that examined thin film has strong red luminescence from standard Eu3+ emission lines.W pracy przedstawiono wyniki badań cienkich warstw TiO2 domieszkowanych europem i palladem, w ilości odpowiednio 0,9 % at. i 5,8 % at. Do nanoszenia cienkich warstw zastosowano wysokoenergetyczny proces (High Energy) rozpylania magnetronowego. Wybrane próbki poddano dodatkowemu poprocesowemu wygrzewaniu. Wyniki dyfrakcji rentgenowskiej (X-Ray Difrraction - XRD) wykazały, że bezpośrednio po naniesieniu otrzymano nanokrystaliczną warstwę TiO2 o strukturze rutylu. Po dodatkowym wygrzewaniu w temperaturze 800°C średnia wielkość krystalitów wzrosła około dwukrotnie (z 9 do 16 nm). Wyniki badań XRD zostały potwierdzone za pomocą badań wykonanych za pomocą mikroskopu sił atomowych. Właściwości optyczne cienkich warstw określono na podstawie wyników badań metodą transmisji światła. Uzyskane wyniki wykazały, że domieszkowanie Eu i Pd spowodowało spadek przezroczystości warstwy o ~ 15% i przesunięcie krawędzi absorpcji optycznej w stronę dłuższych fal (z 330 do 450 nm) w porównaniu do warstwy niedomieszkowanego TiO2. Szerokość optycznej przerwy zabronionej dla cienkiej warstwy TiO2:(Eu, Pd) po naniesieniu wynosiła 1,7 eV i była około dwukrotnie mniejsza w porównaniu do 3,35 eV dla warstwy TiO2. Wyniki badań foto-luminescencji pokazały, że badana warstwa wykazuje silną czerwoną luminescencję odpowiadającą standardowym linią emisyjnym Eu3+