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Full-Text Articles in Physics
Defect Structure Of Sb2−Xmnxte3 Single Crystals., Jaromír Horák, Petr LošŤÁK, Čestmír Drašar, Jeffrey Dyck, Zengzua Zhou, Cterid Uher
Defect Structure Of Sb2−Xmnxte3 Single Crystals., Jaromír Horák, Petr LošŤÁK, Čestmír Drašar, Jeffrey Dyck, Zengzua Zhou, Cterid Uher
Jeffrey Dyck
Incorporation of the transition metal elements in the tetradymite structure of Sb2Te3 has a strong influence on electronic properties. Recent studies have indicated that Mn substitutes on the Sb sublattice increases the carrier concentration of holes. However, the doping efficiency of Mn appears rather low in comparison to what it should be based on the measurements of magnetization, structural analysis, and transport properties. In this paper we address this issue by making detailed studies of the Hall effect and electrical resistivity and we explain the results with the aid of a model that takes into account interactions of the Mn …
Decoherence As A Measure Of Entanglement, Padmanabhan Aravind, Denis Tolkunov, Vladimir Privman
Decoherence As A Measure Of Entanglement, Padmanabhan Aravind, Denis Tolkunov, Vladimir Privman
Padmanabhan K. Aravind
For a solvable pure-decoherence model, we confirm by an explicit model calculation that the decay of entanglement of two state systems (two quibits) is approximately governed by the product of the suppression factors describing decoherence of the subsystems, provided that they are subject to uncorrelated sources of quantum noise. This demonstrates an important physical property that separated open quantum systems can evolve quantum mechanically on time scales larger than the times for which they remain entangled.
Transport Coefficients Of Titanium-Doped Sb2te3 Single Crystals., Č. Drašar, M. Steinhart, P. Lošťák, H.-K. Shin, Jeffrey Dyck, C. Uher
Transport Coefficients Of Titanium-Doped Sb2te3 Single Crystals., Č. Drašar, M. Steinhart, P. Lošťák, H.-K. Shin, Jeffrey Dyck, C. Uher
Jeffrey Dyck
Titanium-doped single crystals (cTi=0–2×1020atomscm−3) were prepared from the elements Sb, Ti, and Te of 5N purity by a modified Bridgman method. The obtained crystals were characterized by measurements of the temperature dependence of the electrical resistivity, Hall coefficient, Seebeck coefficient and thermal conductivity in the temperature range of 3–300K. It was observed that with an increasing Ti content in the samples the electrical resistivity, the Hall coefficient and the Seebeck coefficient increase. This means that the incorporation of Ti atoms into the Sb2Te3 crystal structure results in a decrease in the concentration of holes in the doped crystals. For the …
Low-Temperature Ferromagnetic Properties Of The Diluted Magnetic Semiconductor Sb2-X Crx Te3 ., Jeffrey Dyck, Č. Drašar, P. LošŤÁK, C. Uher
Low-Temperature Ferromagnetic Properties Of The Diluted Magnetic Semiconductor Sb2-X Crx Te3 ., Jeffrey Dyck, Č. Drašar, P. LošŤÁK, C. Uher
Jeffrey Dyck
We report on magnetic and electrical transport properties of Sb2-x Crx Te3 single crystals with 0⩽x⩽0.095 over temperatures from 2 K to 300 K . A ferromagnetic state develops in these crystals at low temperatures with Curie temperatures that are proportional to x (for x>0.014 ), attaining a maximum value of 20 K for x=0.095 . Hysteresis below TC for the applied field parallel to the c axis is observed in both magnetization and Hall-effect measurements. Magnetic as well as transport data indicate that Cr takes the 3+ (3 d3 ) valence state, substituting for antimony in the host …
Thermal And Conductivity Studies Of Chitosan Acetate-Based Polymer Electrolytes, Zurina Osman
Thermal And Conductivity Studies Of Chitosan Acetate-Based Polymer Electrolytes, Zurina Osman
Zurina Osman
Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) have been employed to study the thermal stability of the chitosan acetate-based polymer electrolyte films. The glass transition temperature, T-g measurements confirm the conductivity enhancement effect by adding the plasticizer and salt in the chitosan acetate films
Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina Othon, Fred Bateman, Stephen Ducharme
Effects Of Electron Irradiation On The Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films, Christina Othon, Fred Bateman, Stephen Ducharme
Christina M Othon
The effect of irradiation on the ferroelectric properties of Langmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluoroethylene) was investigated using 1‐MeV electrons for doses from 0.16 to 1.10 MGy, where 1 Gray (Gy) = 100 rad. Irradiation causes a systematic decrease in the phase-transition temperature, crystallinity, and spontaneous polarization of the films. The crystallinity and spontaneous polarization of the films decreased by amounts proportional to the dose, both tending toward zero near a dose of 1.30 MGy. The ferroelectric-paraelectric phase-transition temperature, however, was only reduced by about 12%, indicating that the primary effect of irradiation was to convert a crystalline ferroelectric …
Approximate Solutions For Magmon Propagation From A Reservoir, Tim Marchant
Approximate Solutions For Magmon Propagation From A Reservoir, Tim Marchant
Tim Marchant
A 1D partial differential equation (pde) describing the flow of magma in the Earth's mantle is considered, this equation allowing for compaction and distension of the surrounding matrix due to the magma. The equation has periodic travelling wave solutions, one limit of which is a solitary wave, called a magmon. Modulation equations for the magma equation are derived and are found to be either hyperbolic or of mixed hyperbolic/elliptic type, depending on the specific values of the wave number, mean height and amplitude of the underlying modulated wave. The periodic wave train is stable in the hyperbolic case and unstable …