ZnO thin films were firstly prepared on Si(111) substrates using radio frequency magnetron sputtering system. Then the samples were annealed at different temperature in oxygen ambient and their properties were investigated particularly as a function of annealing temperature. The microstructure, morphology and optical property of ZnO films were studied by XRD, AFM, FTIR and PL. The results show that the increase of annealing temperature leads to the improvement in the crystal quality.

LiNb $_{1-x}$ Tax O3 thin films were successfullydeposited on Pt(111)/Ti/SiO2/Si(100) substrates by spin coatingwith a diol-based sol-gel technology and rapid thermal annealing.The effects of various processing parameters, including Ta content(0 $\leq x\leq1$ ) and heating temperature (500 ~ 800 °C), onthe growth and properties of thin films were investigated. With theincrease of Ta content, the grain size of film decreased slightly,and the maximum f factor (the degree of c-axis orientation) ofthe films were obtained in the composition of x = 0.2. As thecomposition of film varied from x = 0 to x = 1, the relativedielectric constant of film increased from 33 up to 62, and thedielectric loss factor (tanδ) also increased from 0.00374 to0.00686, respectively. The coercive field, Ec, and remanentpolarization, Pr, decreased but pyroelectric coefficient, γ,increased from 2.76 × 10−8 up to 4.51 × 10−8 C/cm2 K. The pyroelectric figures of merit, Fv and Fm,indicated that film with Ta content of 20 mol% and heatingtemperature of 700 °C exhibited the optimized pyroelectriccharacteristics and could be applied for high-performancepyroelectric thin-film detectors.

The chalcopyrite CuAlS2 compound was grown from stoichiometric melt by horizontal Bridgman method. The obtained ingots were crushed finely and annealed at different temperatures from 800 °C to 1100 °C under a gas mixture of 5% N2/H2 atmosphere. X-ray diffraction and Raman spectroscopy were used to investigate the layer microstructures, as well as their lattice vibration spectra. The layers were characterized by scanning electron microscopy (SEM) and the compositional analyses were done by energy dispersive X-ray microanalysis (EDX). Raman measurements of the as made powder indicated seven prominent peaks at 205, 250, 290, 340, 369, 418 and 457 cm−1 with large intensity at 457 cm−1. The peaks at 205, 250, 340 and 457 cm−1 were ascribed to B 2 modes while the peaks 369 and 418 cm−1 were ascribed to E modes. The peak at 290 cm−1 may be assigned to the A 1 mode. After annealing, the Raman features become better and phonon mode at 290 cm−1 looks more distinct. The stoichiometric CuAlS2 compound was obtained when the sample was annealed at 900 °C.

Hydrogenated nanocrystalline silicon carbide (nc-SiC:H) thin films were prepared by reactive magnetron sputtering. Deposition was achieved in a plasma of argon (Ar) and an hydrogen (H2) gas mixture with various H2 dilution percentages (10–80% H2) at a fixed substrate temperature of 500 °C. In order to describe the local bonding and the relative proportion of the different complexes formed during growth, the films were investigated by means of Fourier Transform Infrared absorption and Raman spectroscopy. Other structural features were analyzed by AFM measurements, electron diffraction and high resolution transmission electron microscopy observations. Optical and electrical properties of the films were also characterized. This study shows that hydrogen dilution plays an important role on the microstructure of the films as well as on their properties. The highest refractive index was obtained for a 60% ratio of hydrogen in the plasma and the highest dark conductivity found was 2.03 × 10−4 Ω−1 cm−1. A close relationship between the Si-H bond content and the conductivity is confirmed.

Peculiar nuclear spin systems can be polarized at a level ofthousands times the value obtained at thermal equilibrium, for instance byoptical pumping. When concentrated, these systems create a sizeable averagedipolar field which is experienced by any nuclear spin. We propose to use thesedistant dipolar fields for performing a polarization transfer in theHartmann-Hahn conditions. We report the maximum enhancement value calculatedusing the spin temperature approach and first theoretical insights on thepolarization transfer rate. Using, as an example, dissolved laser-polarizedxenon, we show that by spin-locking both xenon spins and a proton spin of asolute, the polarization of the latter is enhanced. This is obtained withoutthe existence of chemical interaction between the two entities and withcharacteristic rising time not directly correlated to the protonself-relaxation time. By its generality and its non-local feature, thisapproach could make possible nuclear magnetic resonance spectroscopy on verydilute systems.

Direct low temperature plasma (LTP) has been studied for some years now as an alternative eco-friendly technology for achieving shrink-resistant wool fabrics, its action being attributed to the varied active species existing in the plasma. In this paper, for the first time, the efficiency of a post-discharge plasma treatment on the shrink-resistance of wool fabrics has been evaluated. The density of active species present in the nitrogen plasma post-discharge (PD) has been determined by optical spectroscopy and their effects on the increase of hydrophilicity at different treatment times have been recorded through drop test and contact angle techniques. Analysis of the surface by X-ray Photoelectron Spectroscopy (XPS) has shown the increase in N and O – containing functionalities. The post-discharge has shown to be effective in reducing the area shrinkage of the fabrics and its effects have been compared to those obtained by direct LTP.

A three-dimensional finite element method is applied to model a magnetic force control device. This device is based on the use of a magnetostrictive rod in order to control the magnetic force applied to a movable yoke. The paper introduces an original approach to model magnetostrictive phenomena and presents comparisons between numerical and experimental results.

While silicon is not the best semi-conductor material to design Hall effect sensors, it is widely used because Hall devices are fully compatible with standard processes such as CMOS or Bi-CMOS.Hall effect sensors can thus take advantage of on-chip circuitry to counterbalance the poor intrinsic metrological characteristics of silicon Hall devices, and low cost integrated smart magnetometers can be designed using standard technologies.Conventional Hall plate as well as the spinning-current method, which is the present state of the art technique to improve performances of integrated Hall devices, are reviewed in this paper.Then a new multi-strips Hall device and its specific biasing circuit are introduced.This new device allows to multiply by n the absolute sensitivity of the Hall sensor where n is the number of strips, but it suffers from offset.To overcome this drawback, a Hall sensors network which also allows to increase the sensitivity while reducing the offset is proposed.Finally a comparison between the Hall sensors network and the spinning-current is done, showing that both techniques are complementary and should be combined to design high resolution Hall sensor systems.

In this article, a pressure-controlled sample holder for microwave dielectric measurements in the temperature range from 90–450 K is presented. The experimental set-up involves a coaxial line used to couple a microwave frequency network analyzer and an adapted sample holder in order to obtain dielectric characterization as a function of the temperature. The main innovation of the present work is the technical adaptation in the pressure control of the sample for low temperature measurements. The system was tested characterizing the complex dielectric constant of a Ca modified strontium titanate (SrTiO3) quantum paraelectric-type ceramic material, for which the main physical dielectric properties (orientational or relaxation polarization) in the high frequency region are interesting to be investigated mainly at low temperatures.

The effects of turbulence on momentum, heat and solutal transport in a typical high power laser surface alloying process are numerically investigated. The turbulent transport is accounted for by employing a standard high Reynolds number k − ε model, suitably modified to take into account a dynamic evolution of the phase changing interfaces. Phase transitions are handled by using a modified enthalpy porosity technique. Diffusive effects associated with turbulence are found to significantly affect the momentum and solutal transport in the molten pool. On the other hand, enhancements in thermal diffusion on account of turbulence turn out to be rather marginal, with the molecular and eddy thermal diffusivities approximately of the same order. The generation and dissipation rates of turbulent kinetic energy are shown to be in local equilibrium. Based on this inference, a scaling analysis is also performed, which provides order of magnitude estimates of melt pool penetration, mean surface velocity, and temperature/concentration scales. The above estimations are found to be in good agreement with numerical simulation results, in an order of magnitude sense.