Recent development and application of thermoelectric generator and cooler

Thermoelectric cooler and thermoelectric generator devices: A review of present and potential applications, modeling and materials

A memory cell in a 3-D read and write memory device has two bipolar resistance-switching layers with different respective switching currents. A low current resistance-switching layer can be switched in set and reset processes while a high current resistance-switching layer remains in a reset state and acts as a protection resistor to prevent excessively high currents on the low current resistance-switching layer. The low and high current resistance-switching layers can be of the same material such as a metal oxide, where the layers differ in terms of thickness, doping, leakiness, metal richness or other variables. Or, the low and high current resistance-switching layers can be of different materials, having one or more layers each. The high current resistance-switching layer can have a switching current which is greater than a switching current of the low current resistance-switching layer by a factor of at least 1.5 or 2.0, for instance.

Resistive Random Access Memory With Low Current Operation

A memory device in a 3-D read and write memory includes memory cells. Each memory cell includes a resistance-switching memory element (RSME) in series with a steering element. The RSME has first and second resistance-switching layers on either side of a conductive intermediate layer, and first and second electrodes at either end of the RSME. The first and second resistance-switching layers can both have a bipolar or unipolar switching characteristic. In a set or reset operation of the memory cell, an ionic current flows in the resistance-switching layers, contributing to a switching mechanism. An electron flow, which does not contribute to the switching mechanism, is reduced due to scattering by the conductive intermediate layer, to avoid damage to the steering element. Particular materials and combinations of materials for the different layers of the RSME are provided.

Composition Of Memory Cell With Resistance-Switching Layers

First-principles calculations were carried out to study the phase stability and thermoelectric properties of the naturally occurring marcasite phase of FeS2 at ambient conditions as well as under pressure. Two distinct density functional approaches were used to investigate these properties. The plane wave pseudopotential approach was used to study the phase stability and structural, elastic, and vibrational properties. The full potential linear augment plane wave method has been used to study the electronic structure and thermoelectric properties. From the total energy calculations, it is clearly seen that marcasite FeS2 is stable at ambient conditions, and it undergoes a first-order phase transition to pyrite FeS2 at around 3.7 GPa with a volume collapse of about 3%. The calculated ground-state properties, such as lattice parameters, bond lengths, and bulk modulus of marcasite FeS2, agree quite well with experimental values. In addition, phonon dispersion curves unambiguously indicated that the marcasite...

Phase Stability and Thermoelectric Properties of the Mineral FeS2: An Ab Initio Study

Abstracts are not published in this journal

The thermoelectric properties of FeS2

This invention provides a superconducting magnetic shield and a magnetic shielding apparatus including the same, thereby accurately measuring an extremely weak magnetic field such an magnetoencephalographic waves by reducing the influence of magnetic field of the earth or magnetic noises.

Superconducting magnetic shield

We have studied the thermoelectric properties of a SiC-based thermoelectric semiconductor with Ag and polysilastylene (PSS) as a dopant and as a sintering additive, respectively. Ag is an effective dopant to decrease the electrical resistivity of the SiC-based p -type thermoelectric semiconductor. It introduces carrier (hole) concentration 10 3 −10 4 times larger than the case of Al-doped SiC with the typical doping concentration. PSS can control the sample density, which is one of the important factors in decreasing the electrical resistivity and thermal conductivity of the sintered samples. The figure of merit of the sample with Ag 2.0 wt% and PSS 0.1 wt% was estimated to reach 4 × 10 −4 K −1 at 700 °C. This value implies that the SiC/Ag system is one of the promising thermoelectric materials for a high-temperature region.

Temperature and porosity dependence of the thermoelectric properties of sic/ag sintered materials

We fabricated thin films of p-type SiC by the evaporation technique with metal dopants such as silver, nickel and copper, which acted as acceptors. The thermoelectric properties of SiC thin films were measured. These p-type dopants could reduce the resistance of SiC films and improve their performance as thermoelectric materials. For samples doped with 5 wt% Ag, the resistivity is very low compared with those of other samples. The thermoelectric power of the Ag-doped sample shows a temperature dependence in contrast to those of other samples.

https://iopscience.iop.org/article/10.1143/JJAP.38.4852/pdf

Thermoelectric Properties of and Dopant Distribution in SiC Thin Films

In the previous paper, it was reported that the thermoelectric properties of SiC/B4C system could be controlled by the addition of PSS at room temperature. In this report, the porous structure of these samples were confirmed by using SEM, and the measurements were carried out on the temperature dependence of the thermoelectric properties from room temperature up to 600 °C (the thermal conductivity up to 300 °C). Hie figure of merit of the sample (B4C: 2.0 wt.% + PSS: 5.0 wt. %) is estimated about 2 × 10− 6 K− 1 around 600 °C.

Kazuhiko Kato

Papers

The thermoelectric properties of FeS2

Superconducting magnetic shield

Temperature and porosity dependence of the thermoelectric properties of sic/ag sintered materials

Thermoelectric Properties of and Dopant Distribution in SiC Thin Films

Temperature Dependence of the Porosity Controlled SiC/B4C+PSS Thermoelectric Properties