Spectroscopic analysis of nanosized Zn(Ag, Ni)O systems and observation of superparamagnetism at low temperature.

To understand the impact of binary doping in ZnO, nanosized Zn(Ag, Ni)O systems were synthesized by the sol-gel method. The amount of Ag was fixed at 2 at%, and that of Ni was varied from 1 to 15 at%. Ni incorporation equal to or beyond 3 at% gave rise to the development of the NiO phase.

Metal to insulator transition, colossal Seebeck coefficient and large violation of Wiedemann-Franz law in nanoscale granular nickel.

We report on the electrical and thermal transport properties of nickel nanoparticles with crystallite size from 23.1 ± 0.3 to 1.

Ultralow Thermal Conductivity and Large Figure of Merit in Low-Cost and Nontoxic Core-Shell Cu@CuO Nanocomposites.

Identification of novel materials with enhanced thermoelectric (TE) performance is critical for advancing TE research. In this direction, this is the first report on TE properties of low-cost, nontoxic, and abundant core-shell Cu@CuO nanocomposites synthesized using a facile and cheap solution-phase method. They show ultralow thermal conductivity of nearly 10 of the copper bulk value, large thermopower of ∼373 μVK, and, consequently, a TE figure of merit of 0.

Enhanced Thermoelectric Performance of Novel Reaction Condition-Induced BiS-Bi Nanocomposites.

This is the first report on the enhanced thermoelectric (TE) properties of novel reaction-temperature () and duration-induced BiS-Bi nanocomposites synthesized using a facile one-step polyol method. They are well characterized as nanorod composites of orthorhombic BiS and rhombohedral Bi phases in which the latter coats the former forming BiS-Bi core-shell-like structures along with independent Bi nanoparticles. A very significant observation is the systematic reduction in electrical resistivity ρ with a whopping 7 orders of magnitude (∼10) with just reaction temperature and duration increase, revealing a promising approach for the reduction of ρ of this highly resistive chalcogenide and hence resolving the earlier obstacles for its thermoelectric application potentials in the past few decades.

Characteristics of martensitic and strain-glass transitions of the Fe-substituted TiNi shape memory alloys probed by transport and thermal measurements.

The electrical resistivity, Seebeck coefficient, thermal conductivity, and specific heat of TiNi Fe (x = 2.0-10.0 at.

The structure and opto-thermo electronic properties of a new (Bi(BiS)I) hexagonal nano-/micro-rod.

The semiconductor optoelectronic properties of an inorganic (Bi(BiS)I) hexagonal nano-/micro-rod are firstly explored herein. Transmittance and thermoreflectance measurements show that (Bi(BiS)I) hexagonal rods possess an indirect gap of 0.73 eV and a direct gap of 1.

Optimization of thermoelectric performance of SrSi2-based alloys via the modification in band structure and phonon-point-defect scattering.

Thermoelectric properties of alkaline-earth-metal disilicides are strongly dependent on their electronic band structure in the vicinity of the Fermi level. In particular, the strontium disilicide, SrSi2 with a narrow band gap of about few tens of meV is composed of non-toxic, naturally abundant elements, and its thermoelectric properties are very sensitive to the substitution/alloying with third elements. In this article, we summarize the thermoelectric performance of substituted and Sr-deficient/Sr-rich SrSi2 alloys to realize the high thermoelectric figure-of-merit (ZT) for practical applications in the electronic and thermoelectric aspects, and also to explore the alternative routes to further improve its ZT value.

Great enhancements in the thermoelectric power factor of BiSbTe nanostructured films with well-ordered interfaces.

An innovative concept of twin-enhanced thermoelectricity was proposed to fundamentally resolve the high electrical resistance while not degrading the phonon scattering of the thermoelectric nanoassemblies. Under this frame, a variety of highly oriented and twinned bismuth antimony telluride (BixSb2-xTe3) nanocrystals were successfully fabricated by a large-area pulsed-laser deposition (PLD) technique on insulated silicon substrates at various deposition temperatures. The significant presence of the nonbasal- and basal-plane twins across the hexagonal BiSbTe nanocrystals, which were experimentally and systematically observed for the first time, evidently contributes to the unusually high electrical conductivity of ~2700 S cm(-1) and the power factor of ~25 μW cm(-1) K(-2) as well as the relatively low thermal conductivity of ~1.