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Lead-zirconate-titanate (PZT) thick films on pre-fired low-temperature co-fired ceramic (LTCC) substrates were characterised and tested for the application of a piezoelectric resonant pressure sensor. The experimentally obtained material parameters for the thick-film (TF) PZT were used in a finite-element (FE) model of the sensor, which was realised in a 3D LTCC structure with a flexible diaphragm. The simulations revealed the trends and helped to optimise the design.

PbZrO3 powders have been prepared by an alkoxide-based sol–gel route, starting from lead acetate, zirconium n-butoxide, and n-butanol as a solvent, and hydrolysed with different amounts of water in neutral and alkaline medium. The local environment of Zr and Pb atoms was pursued from the sol to the dried (150 °C) and heated (400 °C) powders, by extended x-ray absorption fine structure (EXAFS). The analysis of the sol revealed links between Pb and Zr, and even more links between Zr and Zr. The metal neighbourhoods in the dried powders are not influenced by the hydrolysis conditions. Pb-Zr correlations are gradually lost from the sol to the dried and heated powders, while the loss of Zr–Zr correlations is considerably lower.

(lll)-oriented PZT(30/70) (PZT30) thin films were deposited on Pt/Ti/SiO2/Si substrate by Chemical Solution Deposition (CSD). The part of the Si substrates of 500 mum thickness were etched from back side by a wet chemical etching process. The depth of the back-etching was controlled by changing the etching time (residual Si; 25-180 mum). Dielectric and ferroelectric properties for the PZT30 thin films were measured at the back-etched and the un-etched part to clarify the effect of the residual stress on the electrical properties.

In the present study, a new one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) strategy with minor-groove-binder (MGB) technology for the detection of EAV from 40 semen samples of Slovenian carrier stallions was tested. A novel MGB probe (EAVMGBpr) and a reverse primer (EAV-R) based on the multiple sequence alignment of 49 different EAV strain sequences of the highly conserved ORF7 (nucleocapsid gene) were designed. The performance of the assay was compared with different molecular detection methods. Three different primer pairs targeting the ORF1b and ORF7 were used, respectively. The real-time RT-PCR assay was at least 2 log 10 more sensitive than the classical RT-PCR and at least 1 log 10 more sensitive than the primer set used in the semi-nested PCR. The specificities of the amplification reactions were confirmed with biotinylated probes in the PCR-enzyme-linked immunosorbent assay (PCR-ELISA). Under the conditions described in our study, the sensitivity of the real-time RT-PCR was found to be superior to the PCR-ELISA assay. Thus, while the PCR-ELISA method was found to be both relatively demanding and time consuming, better sensitivity coupled with high specificity and speed of the assay makes the real-time RT-PCR a valuable tool for diagnosis of EAV infection.

In this paper, we report on the performance of microwave phase shifters implemented on sol-gel derived Ba0.3Sr0.7TiO3 (BST) thin Alms. Coplanar waveguide (CPW) phase shifters, loaded-line phase shifters, and reflection-type digital phase shifters have been realized on a single alumina substrate covered with a 300 nm-thick BST film. The performances of different types of phase shifting cells are compared. It is shown that the optimally designed digital phase shifters have better performance although the digital nature of the operation limits the range of their possible applications. A figure of merit FoM = 100deg/dB at f = 20 GHz and E = 400 kV/cm is demonstrated for the one-bit digital phase shifter.

A detailed Rietveld analysis of x-ray data, collected at room temperature, was done on ceramics with controlled grain size between 100 nm and 4 mu m for (PbMg1/3Nb2/3O3)0.80-(PbTiO3)0.20 (PMN-PT20), i.e., a compound at the border of the so-called morphotropic phase boundary. With size reduction the polarization rotates within the monoclinic plane from M-B, i.e., P-x=P-y > P-z to M-A, i.e., P-x=P-y < P-z, and finally reaches a rhombohedral phase, i.e., P-x=P-y=P-z, below a critical value of similar to 200 nm without diminishing the amplitude of the polarization. This study provides an easy way to tailor the direction of polarization of these materials.

The purpose of this paper is to present the comparative study of a single-element transducer based on KNN and on lead-based ceramics. A thickness coupling coefficient of 35%, a sound velocity of 5800 m/s and a dielectric constant of 280 are found and make this material suitable for medium and high frequency applications. On the basis of these electromechanical properties, we have used the KLM model to predict the electroacoustic behaviour of a 10 MHz single-element transducer with two matching layers. We show that KNN transducers have performances intermediate between those of PT-based transducers and PMN-based transducers. Finally, performances of a KNN-based transducer are reported and discussed according to non-linear behaviour of the ceramic.

Summary The resazurin reduction assay depends on the ability of metabolically active cells to reduce the resazurin redox dye to resorufin. In the present study we applied and made a diagnostic evaluation of a spectrophotometric application of the resazurin reduction assay to assess the colour change of resazurin reduction in butanol extracted colour to evaluate boar semen quality. Forty-one samples of boar semen from various breeds were included in the study. The absorption peaks for resazurin and resorufin were found to be 610 and 575 nm, respectively. Absorbance at 610 nm, where the minimum overlap of the two peaks was observed, was used in further analysis. Spearman rank correlation analysis was used to determine the correlation between the resazurin reduction assay and various semen parameters. The highest correlations were observed with the concentration of motile spermatozoa (r = −0.841; p

In the last two decades ferroelectric thin films (FTFs) have been one of the major fields of research in functional-ceramic materials. Both scientific and technological interests have been driven by the potential applications for these materials, in particular in microelectronics and micro-electromechanical systems (MEMS). Two annual conferences have been devoted to the fundamental and applications issues of FTFs: the Ferroelectric Thin Films Materials Research Society Symposia [1] and the International Symposia on Integrated Ferroelectrics [2].

Microcystin-LR is the most frequently studied cyclic heptapeptide produced by different genera of cyanobacteria and is hepatotoxic to livestock and human populations. The adverse effects of microcystin-LR on morphology and cytoskeletal elements in different stages of early embryonal development have been studied in vitro. Embryos and whole embryo cultures have been exposed to microcystin-LR (10-100 microM). Actin filaments were visualized by fluorescence staining and the microtubular network labelled by immunostaining. Growth, development and cytoskeleton organization of the embryos embedded in zona pellucida are not affected by microcystin-LR in concentrations up to 100 microM, while whole embryo cell cultures are affected by the presence of microcystin-LR in the culture medium. High microcystin-LR concentrations (100 microM) cause cells to be detached and destroyed, while lower concentrations (10-20 microM) profoundly affect actin and microtubule organization. These effects are confirmed also by the presence of transformed microcystin-LR in all the media at the lowest concentrations. It seems that the changes to the cells are far more serious than that expressed in cell morphology. From our experiments we conclude that the presence of zona pellucida is an effective way of embryo protection against xenobiotics like microcystin-LR.

PZT (PbZr/sub 0.53/Ti/sub 0.47/O/sub 3/ with 6% of PbO and 2% of Pb/sub 5/Ge/sub 3/O/sub 11/) thick films with a low sintering temperature were printed and fired on either pre-fired or green LTCC foils (LTCC 951, Du Pont). The electrical characteristics of these PZT thick films, together with a set prepared on alumina substrates, were compared. The electrical characteristics of the samples fired at 800/spl deg/C deteriorated significantly due to interactions between the LTCC substrate and the PZT layer. It is presumed that the SiO/sub 2/ that diffused from the LTCC into the PZT layers formed low-permitivity lead-based silicates, which are detrimental to the dielectric properties of the PZT.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Sol-gel derived Pb(Zr/sub 0.53/Ti/sub 0.47/)O/sub 3/ films were prepared by spin coating on platinum coated silicon wafers. The sol for deposition was prepared from Zr and Ti alkoxides and different lead precursors-standard lead acetate hydrate and a new lead oxide based precursor. Crystallisation, microstructure and hysteresis properties of these films were studied and compared in order to reveal the features of the two synthesis methods employed.

The authors sintered a Pb/sub 5/Ge/sub 3/O/sub 11/ ceramic sample and determined the parameters which are important for assessing its usefulness for pyroelectric detectors of infrared radiation. They prepared the Pb/sub 5/Ge/sub 3/O/sub 11/ ceramic by a normal sintering procedure and determined its chemical composition, microstructure, and preparation conditions. The ceramics were then studied for dielectric and pyroelectric properties and finally made into 25-150- mu m thin flakes as the active elements of a pyroelectric detector. The optimal detector was built using the ceramics with an excess of GeO/sub 2/. >

Methods for elimination of one of two embryos in twin pregnancies of mares were studied. Transvaginal ultrasound guided punction of yolk sac or allantoic cavity with fluid aspiration was used. Punction was done in 8 mares, pregnant between 22 and 46 days. In six cases, pregnancy did continue normally with one embryo only while in two cases, both embryos died following the procedure.

A modified methoxyethanol sol-gel process was used for the production of PbZrO3 thin films. The new route uses lead oxide [PbO] instead of lead acetate [Pb(OAc)2]. Through the use of this method it is possible to prepare single-phase perovskite materials with improved properties. Examples are given for PbZrO3 thin layers deposited by the spin coating process on TiO2/Pt/TiO2/SiO2/Si substrates from various sols where lead acetate or lead oxide are used as the starting lead compound. The preferred orientation and the perovskite phase content of the films were studied using X-ray diffraction analysis (XRD). Scanning electron microscopy (SEM) was used for microstructural characterization of the films. Dielectric properties were measured as a function of frequency. In this study the influence of the starting lead compound on the characteristics of the sol-gel derived PZ films were investigated.

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

An evaluation of some silicone and epoxy materials for primary chip and top coatings on hybrid circuits and of their relative merits on the basis of humidity and temperature cycling is presented.

Thyroid hormones appear to determine adult testis size in rodents by regulating the period of Sertoli cell proliferation in the neonatal period. In the present study, the correlation between neonatal thyroid hormone levels (T3 and thyroxin, T4) and postpubertal testis size in Simental bulls was examined. T3 and T4 levels were measured in blood plasma from 35 calves immediately after their arrival at the AI centre at age 3-6 months. Testis size (height and width) was measured at 12 months of age in the same live animals. A significant negative correlation (r = -0.55; por = 0.001) was found between T4 and calculated testicular volume using either the Pearson correlation test or linear regression analysis, while the levels of T3 and testis volume showed a negative correlation, although this did not reach statistical significance (r = -0.20, por = 0.05). The results of this study suggest, therefore, that neonatal thyroid hormone levels might have the same effect on testicular size in cattle as they do in rodents.

The aim of the present work was to prepare a monolithic varistor-capacitor element from a commercial ZnO-based varistor and a relaxor based on lead-magnesium niobate. The materials were chosen on the basis of similar sintering temperatures, in the range from 900 to 1000°C. “Sandwich”-structured composite-pellets were uniaxially dry-pressed and sintered at the conditions that lead to shrinkages observed on the pellets of separately sintered materials. The microstructural analysis of the ‘sandwich’ interface revealed a good contact between the two parts without a noticeable interaction layer. Selected functional properties of both varistor and relaxor parts were adequate

The local environment of Zr atoms in amorphous precursors and intermediate products of the thermal treatment leading to perovskite PbZrO 3 ceramic materials is studied by EXAFS. The coordination of Zr depends significantly on the choice of the starting Zr alkoxide. The Zr-O-Zr bond in an amorphous phase persists till the final stage of heating at 800 °C.

We present the dielectric dispersion in a Pb(Fe1/2Nb1/2)O3 (PFN) thin film grown on (001) SrTiO3 substrate from 20 MHz to 20 GHz in the temperature range of 270 to 340 K. In the radio frequency region, the hopping charge transport and associated polar nanoregion and/or domain-wall motion contribute to the spectrum. In the microwave region, relaxational dispersion was observed with a dielectric contribution of Δe ≈ 600 at room temperature having a characteristic frequency (fm)0.4 = 9.8 · (T−T0) Hz, where T0 is 660 K. It is associated with possible mode-softening behavior, related to the onset of polar nanoregions at T0. The dielectric permittivity shows similarities with 1-dimensional Ising model behaviour.

Strain-induced ferroelectricity was observed directly at low temperatures in KTaO3 thin films and the temperature-strain phase diagram was determined. The values of emax and Tmax of the e'(T) curves change with the measuring electrical signal. The temperature dependence of the dielectric constant is fitted by the Curie-Weiss law.

KTaO3 single crystal is an archetypal incipient ferroelectric in which a long-range ferroelectric order does not establish at low temperatures owing to quantum fluctuations. We report on a strong evidence of the ferroelectric phase transition near 60 K revealed by terahertz spectroscopy and microwave permittivity measurements of a polycrystalline KTaO3 thin film on (0001) sapphire substrate prepared by chemical solution deposition. The soft mode behavior is clearly observed in the terahertz (THz) spectra with a minimum frequency at 60 K. At the same temperature microwave permittivity maximum appears. The THz spectra strongly resemble that of strained epitaxial SrTiO3/DyScO3 films: the ferroelectric soft mode is linearly coupled to a central peak which is silent in the paraelectric phase and it becomes coupled to the polarization below the ferroelectric transition temperature with a progressively increasing bare strength.

The temperature dependence of the deuterium NMR line shape was studied in a pentylcyanobiphenyl (5CB) nematic liquid crystal embedded into lecithin-treated and nontreated continuous-pore silica aerogel matrices. In the lecithin-treated matrix the temperature dependence of the NMR absorption spectra of 5CB exhibits a pronounced first-order nematic-isotropic transition, while in the nontreated matrix only a weak discontinuity was found. The observed almost continuous onset of nematic ordering in the latter case appears to be due to the spread of nematic-isotropic-transition temperatures T NI , in different aerogel cavities

The electrocaloric effect (ECE) in inorganic thin film and organic relaxor ferroelectrics is investigated by directly measuring the ECE around room temperature. The results reveal that giant ECEs can be obtained in the high energy electron irradiated poly(vinylidene fluoride-trifluoroethylene) relaxor copolymer and in the La-doped Pb(ZrTi)O3 relaxor ceramic thin films, which are much larger than that from the normal ferroelectric counterparts. The large ECE observed, compared with normal ferroelectrics, is likely caused by the large number of disordered fluctuating polarization entities in relaxor ferroelectrics which can lead to extra entropy contributions and larger ECE.

Sb doped and undoped SnO2 thin solid coatings were prepared by the dip-coating technique via the sol-gel route using a SnCl4 precursor. Aqueous gels of undoped compound were made according to Hiratsuka and doping was achieved through the addition of SbCl3 in the concentration range of 1 - 10 mol%. FT-IR spectroscopy was utilized to determine the influence of Sb dopant on the vibrational modes of oxohydroxo skeleton of the gel. It was found that oxo bridges between Sb dopants and tinoxohydroxo polymeric species were favored in doped gels. Doping brings about a broadening of the x-ray diffraction peaks and increases the infrared reflectivity of the samples (approximately 50%) in the spectral range 4000 - 600 cm-1, due to the formation of the plasma mode. The dip-coating process gives 0.03 - 0.10 micrometers thick films per dipping, depending on the viscosity of the gel and the dopant concentration. The lowest electrical resistivity of the doped SnO2 coating is 1.2.10-2 (Omega) cm and is comparable to the electrical resistivity of the alkoxide derived Sb doped SnO22.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

CuO thin solid coatings on glass and on stainless steel substrates have been prepared by the dip-coating technique. Sols have been made from a cupric acetate precursor using citric acid as a chelating agent. Scanning electron microscopy (SEM) was used for the determination of the structure of the coatings. These consist of particles with the narrow size distribution. The size of particles is around 0.14 micrometers . Specularly reflecting CuO films on stainless steel and glass substrates were prepared in the thickness range from 0.04 micrometers to 0.7 micrometers . The spectral selectivity of the CuO/stainless steel tandem coating was in the range as 0.10 -0.30. Due to the high refractive index of the CuO film the reflectance of the coatings was diminished by the introduction of fumed silica particles in the initial sols which gave a mat appearance to the coatings and increases their solar absorptance for 5%. The CuO coatings produced on glass exhibit a reddish-purple color with chromaticity coordinates which values change as a function of the film thickness. The structural features of the gel and xerogel from which the final oxide coating has been made are discussed on the basis of their FT-IR spectra.

Following an x-ray diffraction study of phase transitions of the piezoelectric perovskite K0.5Na0.5NbO3 the structural changes of the material are studied using extended x-ray absorption fine structure analysis, whereby the neighborhood of Nb atom is determined in the temperature range of monoclinic, tetragonal, and cubic phases. Within the entire range Nb atom is displaced from the center of the octahedron of its immediate oxygen neighbors, as witnessed by the splitting of Nb–O distance. The model shows high prevalence of the displacement in the (111) crystallographic direction of the simple perovskite cell. The corresponding splitting of the Nb–Nb distance is negligible. There is no observable disalignment of the linear Nb–O–Nb bonds from the ideal cubic arrangement, judging from the intensity of the focusing of the photoelectron wave on the Nb–Nb scattering path by the interposed oxygen atom. As a general result, the phase transitions are found as an effect of the long-range order, while the placement ...

Dielectric properties of KTa0.6Nb0.4O3 thin films on polycrystalline alumina substrates prepared by chemical solution deposition were investigated. Dielectric measurements were performed in radio frequency range by patterning planar capacitors on the film surface and in microwave frequency range by split-post dielectric resonator method. The relaxorlike behavior of dielectric properties, which has not been determined in K(Ta, Nb)O3 thin films previously, was unambiguously confirmed by the fit to the Vogel–Fulcher law. The room temperature values of permittivity and dielectric losses, measured at 10 kHz, are 2430 and 0.08, respectively. The corresponding values, measured at 14.5 GHz, are 590 and 0.52.

An exceptionally high dielectric constant was obtained by making use of the conductive percolative phenomenon in all-ceramic composite, comprising of Pb2Ru2O6.5 with high electrical conductivity denoted as the conductive phase and ferroelectric 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (PMN-PT) perovskite systems. Structural analysis revealed a uniform distribution of conductive ceramic grains within the PMN-PT matrix. Consequently, the dielectric response in the PMN-PT-Pb2Ru2O6.5 composite follows the predictions of the percolation theory. Thus, close to the percolation point exceptionally high values of the dielectric constant were obtained—values higher than 105 were detected at room temperature at 1 kHz. Fit of the data, obtained for samples of different compositions, revealed critical exponent and percolation point, which reasonably agree with the theoretically predicted values.

High performance transparent thin-film transistors deposited on glass substrates and entirely processed at a low temperature not exceeding 150°C are presented and analyzed in this paper. Besides being based on an amorphous oxide semiconductor, the main innovation of this work relies on the use of sputtered multicomponent oxides as dielectric materials based on mixtures of Ta 2 O 5 with SiO 2 or Al 2 O 3 . These multicomponent dielectrics allow to obtain amorphous structures and low leakage currents while preserving a high dielectric constant. This results in transistors with remarkable electrical properties, such as field-effect mobility exceeding 35 cm 2 V ―1 s ―1 , close to 0 V turn-on voltage, on/off ratio higher than 10 6 , and a subthreshold slope of 0.24 V decade ―1 , obtained with a Ta 2 O 5 :SiO 2 dielectric. When subjected to severe current stress tests, optimized devices show little and reversible variation in their electrical characteristics. The devices presented here have properties comparable to the ones using plasma-enhanced chemical vapor deposited SiO 2 at 400°C, reinforcing the success of this amorphous multicomponent dielectric approach for low temperature, high performance, and transparent electronic circuits.

The Raman spectra of the ceramics PLZT x/40/60 have been measured in the temperature range 20‐800 K. An assignment of the Raman modes is presented using the results of the effective medium approximation for the IR data. Factor-group analysis is presented for the case of off-site position of cations or unit cell doubling, which allows a higher number of active phonons in the IR and Raman spectra. The presence of Raman-active modes in the cubic phase is associated with local unit cell doubling and symmetry breakdown due to the off-site cations. (Some figures in this article are in colour only in the electronic version)

A huge dielectric anisotropy has been found in Pb0.775La0.15(Zr0.4Ti0.6)O3 (PLZT 15∕40∕60) ceramics by analysis of infrared reflectivity spectra. Anisotropy is present in both the relaxor and the ferroelectric phases. Infrared spectra were evaluated using Bruggeman’s formula within the effective medium approximation. X-ray structural analysis supports a local [110] shift of Pb cations and factor-group analysis taking into account the 4d site symmetry for the effective Pb∕La atom gives more infrared and Raman active phonons than the previous published factor-group analysis, in agreement with our infrared data. Symmetry of all observed polar phonons was assigned.

Phases, domain configuration, and properties of 0.65Pb(Mg1∕3Nb2∕3)O3–0.35PbTiO3 ceramics with grain sizes of 4 and 0.15μm have been studied. The average phase is monoclinic Pm in coexistence with tetragonal. An evolution from micron-sized lamellar domains towards submicron/nanometer sized crosshatched domains is found with the decrease in size, which results in electrical relaxor type behavior and hindered switching. This is proposed to be associated with the slowing down of the relaxor to ferroelectric transition that causes the long time presence of an intermediate domain configuration. Nevertheless, a high sensitivity piezoelectric submicron-structured material is obtained under tailored poling (d33∼300pCN−1).

The dielectric behavior of tetragonal (Pb1−xLax)(Zr0.4Ti0.6)O3 (PLZT x∕40∕60) ceramics doped with lanthanum (x=12% and 15%) has been investigated from 102to1014Hz in the temperature range of 20–800K. Relaxor ferroelectric behavior, together with a first-order ferroelectric phase transition at TC below the dielectric maximum, was revealed. The lowest-frequency phonon partially softens to TC and splits into two components in the ferroelectric phase. It is shown that similar splitting is typical for all relaxors even for samples without ferroelectric phase transitions, because the TO1 splitting occurs due to a local distortion in the polar clusters. A relaxational mode, assigned to the dynamics of polar clusters, was revealed in the teraherz spectra below 800K. This mode slows down to the microwave range on cooling and finally anomalously broadens below TC, which appears to be characteristic for all relaxors. In comparison to the rhombohedral (Pb1−xLa0.095)(Zr0.65Ti0.35)O3, the low-temperature permittivity a...

To check on the nature of the weak magnetic order in polycrystalline magnetoelectric Pb(Fe1∕2Nb1∕2)O3 the X-band, Q-band, and far infrared electron paramagnetic resonance (EPR) spectra have been measured between 4 and 600K and compared with magnetic susceptibility and magnetization data. The asymmetric line shapes can be simulated at higher temperature by thermally fluctuating superparamagnetic nanoclusters. The pronounced temperature dependence of the position of the spectra demonstrates the presence of an internal magnetic field which is small but nonzero even at room temperature, i.e., far above the antiferromagnetic transition. The electronic spin-spin exchange has been found to be in the terahertz range. The magnetization data reveal a weak ferromagnetism even above 300K and a break in the temperature dependence of susceptibility at the paramagnetic to ferromagnetic transition.

The polarization switching is experimentally investigated in hot-pressed PLZT-x/65/35 ceramics with a lanthanum content from 5 to 12 at. %. The specific features in the temperature dependence of the polarization switching in a heterophase state are interpreted by analyzing the change in the switched charge measured over wide ranges of fields and temperatures. Particular emphasis is placed on the role of depolarization fields induced by interphase boundaries. A model of the evolution of polydomain nanostructures with a change in the temperature and in the response to an external field is considered. It is assumed that the low-temperature dielectric anomaly and the temperature hysteresis are associated with the loss of stability of a large-scale domain structure and its transformation into a nanodomain state.

Sintering of Na 0.5 K 0.5 NbO 3 may be activated by slight excess of Nb 5+ ions or by incorporation of Mg 2+ ions into crystal lattice. By this means, high density samples (97% TD) were prepared by conventional sintering technique. Mg-doped sintered samples exhibit increase in k p , some lowering in e and large increase in resistivity after prolonged sintering.