High-quality bismuth telluride crystals having a thickness of only a few atoms were prepared by a method similar to that for graphene mechanical exfoliation. The potential for these materials to be used as thermoelectric materials was then investigated. It was found that the properties of these materials could be fine-tuned by altering the thickness, or the sequence of atomic planes. “Stacked superlattices” were formed using these atomic films, and these ...
In this article, the authors present a novel method for the synthesis of graphene layers that can be used in advanced electronic devices, among other applications. The preparation method involves the use of a high-pressure high-temperature process where the pressure and temperature are closely monitored in order to preferentially prepare graphene layers. The quality of the material synthesized is much better than previously reported, and the size of the layers ...
Yttria-stabilized zirconia (YSZ) was synthesized by the spark plasma sintering process to generate pore-free, homogenous bulk samples that were then tested for thermal conductivity, which was measured by two separate methods: TPS and LFT. The TPS method was found to be better for measuring of thermal conductivity in this specific case. Using the phonon-hopping model (PHM) the authors were able to determine how grain boundaries of the bulk samples affected ...
The 'graphene-like' mechanical exfoliation of Bi2Te3 films is shown to have a significant effect on the thermoelectric properties of these films. The modification of thermal conductivity due to exfoliation leads to enhanced thermoelectric properties, known as figures of merit (ZT).Two different experimental techniques were used in order to determine the thermal conductivity of the exfoliated films: transient plane source (TPS) and laser flash technique (LFT). Annealing was performed ...
Thermal conductivity testing was done on nitrogenated ultrananocrystalline diamond films on silicon. Temperature dependence on thermal conductivity was measured using these two techniques. A decrease in thermal conductivity was observed with the introduction of nitrogen addition. It was observed that MCD had the highest thermal conductivity followed by UNCD at 25% nitrogen and UNCD at 0% nitrogen....
