Titanium nitride (TiNx) thin films, ∼100 nm thick, were deposited on Si(100) substrates by dc reactive magnetron sputtering. The effects of the substrate bias voltage and deposition temperature on their optical, electrical, and mechanical properties have been studied. It was found a strong correlation between the electrical and mechanical properties of the films which are significantly improved with increasing the substrate bias voltage and the deposition temperature. The low resistivity (43 μΩ cm), combined with the high hardness and elastic modulus values, suggest the TiNx as a promising metallization material in Si technology.

Hall-effect measurements in magnetic fields up to 1.5 T are performed on β-FeSi2 films between 20 and 300 K. An anomalous low-field Hall coefficient R1 in addition to the normal high-field Hall coefficient R0 is detected at temperatures below 250 K. The temperature dependence of R0 is explained by a two valence-band model and an impurity level located close to the upper valence-band edge. The temperature dependence of R1 indicates that β-FeSi2 behaves as ferromagnetic below 100 K. Correlation between the coefficient Rs=R1−R0 and the electrical resistivity ρ indicates a drastic change in magnetic ordering at about 70 K.

Polycrystalline semiconducting FeSi2 thin films were grown on (100) Si substrates of high resistivity by electron beam evaporation of amorphous Si/Fe ultrathin multilayers in an ultrahigh vacuum system, followed by conventional vacuum furnace (CF) or rapid thermal annealing (RTA). Infrared reflectance and transmittance measurements were employed for optical characterization of the samples at room temperature. The results indicate a direct transition at about 0.85 eV, an indirect transition at about 0.79 eV, and exponential band tail states within the band gap. The quality of the silicide is improved by increasing the annealing temperature from 600 to 800 °C in the RTA process, while the opposite is observed in the CF annealed samples. Transport measurements were performed on a typical β-FeSi2 layer of high quality grown by CF at low temperature. The measured mobility is about 97 cm2/V s and the hole concentration is about 1×1017 cm−3. The mobility is a factor of 10 higher and the hole concentration a factor of 100 lower than the corresponding published data, indicating a significantly improved quality of β-FeSi2 layers. Temperature-dependent measurements indicate that carrier transport is dominated by impurity conduction.

This study focuses on compulsory education pupils' representations of electric current (14-15 years). The subjects' views in a Greek school were diagnosed and utilised in a constructivist approach to introducing DC circuits. Results suggested that various pupils' views before and during the early stages of instruction can be modelled after an 'energy framework'. The uses of this 'energy framework' in predicting and interpreting several phenomena, e.g. the Oersted experiment, the readings of ammeters in series and the short circuit are presented. After the introduction of the scientific model for current, several pupils' views can be modelled after a 'flow' framework.Considerable conceptual changes towards the scientific model were noted in the post-tests and suggestions are made about the content, the apparatus and the experiments used in the teaching of DC circuits.

We study the effects of the shape of the cross section of a three-dimensional quantum wire on electron scattering from a single point defect in the wire. The confinement of electrons is modeled by both hard- and soft-wall potentials. We find that as the degree of anisotropy of the cross section of the wire is increased intersubband electron scattering is enhanced and intrasubband transmission is suppressed making it appear as though the defect has stronger impact on electron scattering for asymmetric cross sections. Also, increasing the anisotropy of the cross section results in a decrease of the values of the conductance. Furthermore, for the soft-wall confinement the conductance as a function of Fermi energy rises faster than the conductance for the hard-wall confinement. We use the Lippmann–Schwinger equation of scattering theory in order to calculate analytically the transmission coefficients.