Effects of yttrium doping on the thermoelectric properties of Hf 0.6 Zr 0.4 NiSn 0.98 Sb 0.02 half-Heusler alloys A Heusler Fe 2 V 1-x W x Al sintered alloy was synthesized to evaluate the effect of W substitution on thermoelectric properties of the Heusler alloy. The Seebeck coefficient and the electrical conductivity are simultaneously enhanced through electron injection resulting from the W substitution. Comparison with the Si-substituted Fe 2 VAl alloy reveals that the additional electronic states derived from W 5d orbital in the vicinity of pseudogap are likely to degrade the Seebeck coefficient. Thermal conductivity is effectively reduced by the W substitution because of the large atomic mass and volume of W compared to the constituent elements of Fe 2 VAl alloy. The appreciable reduction of thermal conductivity, without a serious deterioration in electrical conduction, enhances the thermoelectric figure of merit in the Heusler alloy. V C 2012 American Institute of Physics.

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This paper reports on the results of comparing different types of tensile testing methods that are used to evaluate thin-film properties. We tested the same material fabricated on a single wafer using different testing techniques at five different research institutions. The testing methods were different in the way the specimen was gripped. Materials tested were single-crystal silicon (SCS), polysilicon, nickel, and titanium films. Specimens with three different shapes were processed through the same fabrication steps. The tensile strength, fracture strain, and Young's modulus of the films were measured and compared. The measured values of the mechanical properties of all the testing methods were in good agreement with each other, thus demonstrating their accuracy.[1123]

We fabricated thin-film thermoelectric modules for thermal–photovoltaic hybrid solar generator. Bi0.5Sb1.5Te3 (p-type) and Bi2Te2.7Se0.3 (n-type) thermoelectric thin films were deposited by radio-frequency magnetron sputtering method and patterned to form plane-type thermoelectric modules using lift-off technique. The hybrid module consisted of the thin-film thermoelectric module, a photovoltaic module, a hot mirror, and a near-infrared (NIR) focusing lens. NIR light, which does not contribute to photovoltaic conversion, was separated from solar light using the hot mirror. When the NIR light was focused onto the hot side of the thermoelectric module by the lens, the open voltage generated by the thin-film thermoelectric generator was 78 mV. The total open voltage of the thermal–photovoltaic hybrid generator increased by 1.3% compared to that of the photovoltaic module alone.

α″-Fe16N2 nanopowder was sintered at high-pressure and low temperature in order to explore its feasibility as a bulk magnet. TEM observation confirmed that the nanopowder was densely consolidated by sintering at a pressure of 1.2 GPa and temperatures around 200 °C. Increasing the sintering temperature enhanced the densification, leading to a suppression of oxidization. However, XRD analysis revealed that sintering at 222 °C caused the decomposition α″ → α-Fe + ε-Fe3N, which reduced the saturated magnetization (Ms) and coercivity (Hc). Consequently, sintering at 190 °C produced a dense magnet that retained the Ms of the raw powder due to the avoidances of oxidization and decomposition. On the other hand, it was found that Hc degrades after sintering, which is believed to be due to magnetic interaction between the particles.

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