Electrical resistivity and conductivity

About: Electrical resistivity and conductivity is a research topic. Over the lifetime, 62162 publications have been published within this topic receiving 1078632 citations.

Bismuth tri-iodide polycrystalline films for X-ray direct and digital imagers

Abstract: Bismuth tri-iodide films were grown by the physical vapor deposition method on gold-coated glass substrates 1 in.×1 in. (2.5×2.5 cm) in size. The growth was performed in a system especially designed and constructed for getting a fine control of the growth parameters. The best growth conditions were a source temperature of 350 °C, a growth temperature of 175 °C and a growth time of 24 h, with an initial pressure of 3×10 −2 Pa. Film thicknesses and grain sizes gave values ranging between 5 and 60 μm (10%), and between 0.5 and 2 μm, respectively. The dark current density of the films is 9.7 pA/mm 2 for an electric field of 5.6 V/μm, and the resistivity is 1.4×10 13 Ω cm. Mobility-lifetime values of 3×10 −7 cm 2 /V can be estimated for electrons. A signal to dark relation of 2.3 was measured at 250 mA and 40 KVp, with an electric field of 1 V/μm applied to the film.

Thermal Expansion, Electrical Resistivity, and Spreading Area of Sn-Zn-In Alloys

Abstract: Thermal expansion and electrical resistivity of alloys based on Sn-Zn eutectic with 0.5, 1.0, 1.5, and 4.0 wt.% additions of In were studied. Thermal expansion measurements were performed using thermomechanical analysis tester over 223-373 K temperature range. Electrical resistivity measurements were performed with four-probe method over 298-423 K temperature range. The electrical resistivity of alloys increases linearly with temperature and concentration of In; also coefficient of thermal expansion of the studied alloys increases with In concentration. Scanning electron microscopy revealed simple eutectic microstructure with In dissolved in Sn-rich matrix. The results obtained were compared with the available literature data. Spreading tests on Cu of Sn-8.8Zn alloys with 0.5, 1.0, and 1.5 at.% of In were performed. Wetting tests were performed at 250 °C, by sessile drop method, by means of flux, and wetting times were 3, 8, 15, 30, and 60 min. In general, no clear effect of wetting time on spreading was observed.

Electrode effects in dielectric spectroscopy measurements on (Nb+In) co-doped TiO2

Abstract: Recently, several papers reported the discovery of giant permittivity and low dielectric loss in (Nb+In) co-doped TiO2. A series of tests was performed which included the measurement of the frequency dependence of the dielectric permittivity and alternating current (ac) conductivity of co-doped (Nb+In)TiO2 as a function of electrode type, sample thickness, and temperature. The data suggest that the measurements are strongly affected by the electrodes. The consistency between four-contact van der Pauw direct current conductivity measurements and bulk conductivity values extracted from two-contact ac conductivity measurements suggest that the values of colossal permittivity are, at least in part, a result of Schottky barrier depletion widths that depend on electrode type and temperature.