The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Anharmonicity in solid materials is a critical factor that dictates a number of observable phenomena, especially those that depend on temperature. However, characterising such interactions is difficult due to the nature in which they combine with other effects, both experimentally and theoretically. This work details how terahertz time-domain and low-frequency Raman spectroscopy, when combined with...
We have developed a reliable and predictable TCAD modeling method for retention characteristics of the charge trap NAND Flash device. This modeling method can explain various retention phenomena related to temperature, program pattern, and bake time. The temperature dependency is well described by direct tunneling and thermionic emission, the pattern dependency can be explained by carrier diffusion...
Through the high temperature X-ray diffraction, structural evolution of Ag70Au30 alloy with varying temperatures has been investigated. The liquid alloy experiences a sudden structure change nearby 1150 °C, which has been further thermodynamically confirmed by Differential Scanning Calorimetry (DSC). Small pre-peaks have been found in the structure factor (S(Q)) curves, indicating the stable medium-range...
This paper examines the temperature dependence of mismatching and harmonic distortion properties in nanoscale uniaxial strained pMOSFETs. Our results reveal that the temperature dependence of drain current mismatch as well as harmonics distortion can be modulated by uniaxial strain. In the high gate-voltage overdrive (|Vgst|) linear region, the compressively-strained device shows smaller increment...
We measured, in the 873-1173 K temperature range, the temperature- and Cd vapor-pressure-dependences of the free electron density in single Cd1-xZnxTe≪In≫ (0 ≤ × ≤ 0.1) crystals with different In contents. Increasing the cooling rate of the crystals and/or decreasing the well-defined Cd vapor pressure reduced the free-electron density. We interpreted and modelled these phenomena and the crystal’s...
Ionic conductivity of composites MeClO4-Al2O3 (Me = Li, Na, K, Rb and Cs) was investigated. It was found that in all composites the conductivity goes through a maximum. Maximum conductivity was observed for nanocomposites based on lithium perchlorate which are promising solid electrolytes for intermediate temperature solid state electrochemical devices.
ldquoDevelopment for advanced thermoelectric conversion systemsrdquo supported by the new energy and industrial technology development organization (NEDO) has been successfully completed as one of the Japanese national energy conservation projects. Three types of the cascaded thermoelectric modules operating up to 850 K in high electrode temperature and two types of Bi-Te thermoelectric modules operating...
Thermoelectric properties of ternary silver thallium tellurides: Ag8T12Te5 and AgT13Te2 were studied above room temperature to slightly below the melting temperature. As for Ag8T12Te5, the effects of Te content on the thermoelectric properties were also studied by characterizing the samples of Ag8T12Tex (x = 5.0, 5.1, 5.2). Both compounds show positive Seebeck coefficient (S). Ag8T12Te5 indicates...
Thermoelectric and galvanomagnetic properties have been studied in n-Bi2-xSbxTe3-y-zSeySz and p-Bi2-xSbxTe3-y-zSey multicomponent solid solutions with various atomic substitutions in both sublattices of Bi2Te3. Anisotropy of the constant energy surface and charge carrier scattering was determined within the framework of a many-valley-model of energy spectrum using isotropic and anisotropic scattering...
A theoretical model is proposed in this work for an evaluation of the specific heat and Debye temperature of thin-film semiconductors. In the model, the specific heat contributed by the confined acoustic phonons is calculated first. An effective Debye temperature is then defined by fitting the conventional Debye model to the calculated specific heat. It is found that the so-defined Debye temperatures...
The polycrystalline samples of BaSi2, SrSi2, and LaSi were prepared by spark plasma sintering (SPS). The electrical resistivity (rho) and Seebeck coefficient (S) were measured above room temperature. The S of BaSi2 was negative and the absolute values were rather high (-669 muVK-1 at 337 K). The S of SrSi2 was positive and the absolute values were lower (118 muVK-1 at 332 K) than those of BaSi2. For...
We report thermoelectric characterization of Bi2-xSbxTe3 (x = 0.5, 1.0, and 1.5) synthesized by a solvothermal method using DMF as solvent. For Bi2Te3, the size of the edge and thickness of the hexagonal nanoplatelets are 200-250 nm and 20-25 nm, respectively. Bi2Te3 nanosheets appear to grow epitaxially from the surface of the Te tubes, which forms in the first step and acts as the template for the...
Bulk nanostructured (Bi,Sb)2Te3 compounds and GeTe based amorphous/nanocrystal composites have been successfully fabricated by the combined hydrothermal/hot-pressing and quenching/annealing methods, respectively. The (Bi,Sb)2Te3 nanopowders synthesized by hydrothermal method exhibit a hollow-like structure. After hot-pressing, the nanoscale grains varying from tens to hundreds of nanometers were found...
The SrTiO3 and Y-doped SrTiO3 polycrystalline sintered bodies were synthesized by the polymerized complex (PC) process and the subsequent hot pressing at 1473 K for 1 h or at 1673 K for 2 h in Ar atmosphere. The X-ray diffraction patterns of the SrTiO3 and Sr0.9Y0.1TiO3 samples synthesized by the PC process and hot pressing at 1473 K showed that these samples were mostly composed of the SrTiO3 single...
Hf1-xZrxTe5, which is expected to have high thermoelectric performance at low temperature, is investigated on polycrystals with high density. in order to examine the possibility of large enhancement of the figure of merit at low temperature, polycrystalline samples of Hf1-xZrxTe5 (x=0.0, 0.5 and 1.0) are systhesized by hot-press sintering to make high density above ~90%. Resultant polycrystals show...
In this study, we fabricated in-plane thermoelectric micro-generators (4 mm times 4 mm) based on bismuth telluride thin films by using flash evaporation method. The thermoelectric properties of as-grown thin films are lower than those of bulk materials. Therefore the as-grown thin films were annealed in hydrogen at atmospheric pressure for 1 hour in a temperature range of 200 degC. to 400degC. By...
Nanostructuring is one of the effective approaches to lower the thermal conductivity of materials. Nanostructured skutterudite-related compounds CoSb3, Fe0.5Ni0.5Sb3, Fe0.25Ni0.25Co0.5Sb3 and Te-doped CoSb3 were synthesized by a solvothermal route. The bulk materials were prepared by hot pressing or spark plasma sintering from the solvothermally synthesized nanopowders. The thermal conductivity values...
Optical communication systems based on dense wavelength division multiplexing (DWDM) would benefit from the ability to adjust the operating wavelength of a laser transmitter. Previous attempts, including thermal adjustment, etalon based wavelength locking, and various types of optical frequency and phase locked loops such as the Pound-Drever-Hall technique suffer from weaknesses including sensitivity...
Liquid and plastic polytrifluoromonochloroethylene polymers exhibit similar electrical behavior as a function of temperature and frequency. As the temperature is lowered, one passes from a single phase (either solid or liquid depending on average molecular weight) to a two-phase state characterized by the appearance of crystallites in the material. The temperature at which crystals appear depends...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.