For the first time, latent heat of fusion $\ensuremath{\Delta}{H}_{m}$ for Sn particles formed by evaporation on inert substrate with radii ranging from 5 to 50 nm has been measured directly using a novel scanning nanocalorimeter. A particle-size-dependent reduction observed. An ``excluded volume'' is introduced describe enhanced surface melting small particles. Melting point depression also found our nanocalorimetric technique.

ZnO is a promising high figure-of-merit (ZT) thermoelectric material for power harvesting from heat due to its melting point, electrical conductivity σ, and Seebeck coefficient α, but practical use limited by lattice thermal κ(L). Here, we report Al-containing nanocomposites with up factor of 20 lower κ(L) than non-nanostructured ZnO, while retaining bulklike α σ. We show that enhanced phonon scattering promoted Al-induced grain refinement ZnAl(2)O(4) nanoprecipitates presages ultralow κ ∼ 2...

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Nitrogen (15N) and carbon (12C) ion implantations with implant energy of 100 keV for different doses were performed on nanosized diamond (ND) particles. Magnetic measurements the doped ND show ferromagnetic hysteresis behavior at room temperature. The saturation magnetization (M(s)) in case 15N implanted samples was found to be higher compared 12C dose sizes greater than 10(14) cm(-2). role structural modification or defects along carbon-nitrogen (C-N) bonding states observed enhanced...

This paper investigates the change in contact angle of droplets fluid containing dispersed nanoparticles (nanofluid) functionalized with thioglycolic acid molecules as a function concentration and size nanoparticles, quality composition substrate material. Bismuth telluride an average ranging from 2.5 to 10.4 nm groups were grown by microemulsion method water. Experimental measurements nanofluid cast on smooth glass silicon substrates show that depends strongly nanoparticle concentration....

Magnetic electrospun fibers are of interest for minimally invasive biomaterial applications that also strive to provide cell guidance. can be injected and then magnetically positioned in situ, the aligned fiber scaffolds consistent topographical guidance cells. In this study, responsive poly-l-lactic acid were developed tested neural applications. Incorporating oleic acid-coated iron oxide nanoparticles significantly increased neurite outgrowth, reduced alignment, surface nanotopography...

We report highly substrate-site selective growth of carbon nanotubes by chemical vapor deposition from precursors ferrocene and xylene mixtures. The technique allows us to grow well-aligned multiwalled preferentially on the SiO2 regions patterned SiO2/Si substrates prepared conventional lithography. This eliminates catalyst predeposition step in fabrication process. simple approach may also be applied build large-scale networks organized planar substrates.

We introduce a high sensitivity (1J/m2) scanning microcalorimeter that can be used at heating rates (104 °C/s). The system is designed using ultrathin SiN membranes serve as low thermal mass mechanical support structure for the calorimeter. Calorimetry measurements of are accomplished via resistive techniques applied to thin film Ni element also serves thermometer. A current pulse through heater generates heat in sample Joule heating. voltage and characteristics were measured obtain...

Antimony selenide is a promising thermoelectric material with high Seebeck coefficient, but its figure of merit limited by low electrical conductivity. Here, we report rapid and scalable (gram-a-minute) microwave synthesis one-dimensional nanocrystals sulfurized antimony that exhibit ∼104−1010 times higher conductivity than non-nanostructured bulk or thin film forms this material. As the nanocrystal diameter increases, nanowires transform into nanotubes through void formation coalescence...

Antimony telluride has a low thermoelectric figure of merit (ZT < ∼0.3) because Seebeck coefficient α arising from high degenerate hole concentrations generated by antimony antisite defects. Here, we mitigate this key problem suppressing defect formation using subatomic percent sulfur doping. The resultant 10-25% higher in bulk nanocrystalline leads to ZT ∼ 0.95 at 423 K, which is superior the best non-nanostructured alloys. Density functional theory calculations indicate that increases...

Realizing high thermal conductivity nanocomposites is a challenge because of difficulties in incorporating fractions uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance. Here, we obviate these issues by using &amp;lt;3 vol. % gold nanowire fillers to obtain 30-fold increase polydimethylsiloxane that 6-fold higher than any nanocomposite at nanofiller loadings exceeds theoretical predictions. The diameter aspect ratio are keys obtaining cold-welded networks...

Bismuth telluride (Bi2Te3) based alloys are preferred thermoelectric materials for room temperature applications. Electrical transport and thermopower properties of n-type nanostructured BixSb2-xTe3 films were tuned by post-growth heat treatment. We report that annealing sputter-deposited Bi0.7Sb1.3Te3 lead to several-fold increases in power factor α2σ, where σ is electronic conductivity α Seebeck coefficient. Annealing at Tanneal = 200 °C nearly quadruples the α2σ 3.1 μW cm−1 K−2....

ZnO is a high melting point, charge carrier mobility semiconductor with potential as thermoelectric material, but its thermal conductivity κ the limiting factor for increasing figure of merit ZT. Here, we demonstrate that doping heavy elements can significantly enhance Indium leads to ultralow ∼ 3 W m−1 K−1 and power α2σ 1.230 × 10−3 K−2, yielding ZT1000K 0.45 ∼80% higher than non-nanostructured In–Zn–O alloys. Although Bi also yields Seebeck coefficient α300K 500 μV K−1, segregation, grain...

Controllable assembly of ordered nanoscale structural units in geometrically well-defined configurations is essential for building integrated systems. Here, we describe a powerful method to simultaneously grow aligned carbon nanotube bundles multiple, predetermined orientations on planar substrates build one- three-dimensional architectures. We effect multidirectional growth by gas-phase delivery xylene−ferrocene mixture lithographically machined silica surface templates. The preference...

Devising ultrathin barrier layers to prevent Cu diffusion into SiO2-based dielectrics is a major challenge that must be met increase the speed, number density, and performance of microelectronics devices. Here, we demonstrate use near-zero-thickness (&amp;lt;2-nm-thick) self-assembled molecular monolayers (SAMs) as candidates for this application. Cu/SiO2/Si(001) metal–oxide–semiconductor capacitors, with without SAMs at Cu/SiO2 interface, were annealed 200 °C in 2 MV cm−1 electrical field....

Preserving the structural and functional integrity of interfaces inhibiting deleterious chemical interactions are critical for realizing devices with sub-50 nm thin films nanoscale units. Here, we demonstrate that ∼0.7-nm-thick self-assembled monolayers (SAMs) comprising mercapto-propyl-tri-methoxy-silane (MPTMS) molecules enhance adhesion inhibit Cu diffusion at Cu/SiO2 structures used in device metallization. Cu/SAM/SiO2/Si(001) show three times higher interface debond energy compared to...

Sb doping stabilizes the chemically ordered tetragonal L10 structure in FePt alloy nanoparticles, yielding higher coercivities (Hc) at lower annealing temperatures (see Figure) than previously reported. Upon to ∼ 300 °C, nanoparticles yield more ten times those reported for of similar sizes annealed same temperature. These findings are importance ultrahigh-density memory device applications.

Chalcogenide nanostructures offer promise for obtaining nanomaterials with high electrical conductivity, low thermal and Seebeck coefficient. Here, we demonstrate a new approach of tuning the coefficient nanoplate assemblies single-crystal pnictogen chalcogenides by heterostructuring nanoplates tellurium nanocrystals. We synthesized bismuth telluride antimony decorated nanorods nanofins using rapid, scalable, microwave-stimulated organic surfactant-directed technique. Heterostructuring...

We demonstrate a microprobe technique that can simultaneously measure thermal conductivity κ and Seebeck coefficient α of thin films. In this technique, an alternative current joule-heated V-shaped microwire serves as heater, thermometer voltage electrode, locally heats the film when contacted with surface. The is extracted from resistance measured between probe unheated regions by modeling heat transfer in probe, sample their contact area, calibrations standard reference samples....

Dilute isovalent sulfur doping simultaneously increases electrical conductivity and Seebeck coefficient in Bi2Te2Se nanoplates, bulk pellets made from them. This unusual trend at high electron concentrations is underpinned by multifold effective mass attributable to sulfur-induced band topology effects, providing a new way for accessing thermoelectric figure-of-merit topological-insulator-based nanomaterials through doping. As service our authors readers, this journal provides supporting...

Realizing stress-free inorganic epitaxial films on weakly bonding substrates is of importance for applications that require film transfer onto surfaces do not seed epitaxy. Film-substrate usually weakened by harnessing natural van der Waals layers (e.g., graphene) substrate surfaces, but this difficult to achieve in non-layered materials. Here, we demonstrate epitaxy a material VO2 mica. The exhibit out-of-plane 010 texture with three in-plane orientations inherited from the crystallographic...