Stoner-enhanced paramagnetism in tungsten tetraboride.

We demonstrate that tungsten tetraboride (WB4), a heavy transition metallic compound without magnetic atoms, is an exchange-enhanced paramagnet revealed by the magnetization and specific heat measurements. WB4 has a small effective magnetic moment of 0.53 μB/fu.

Fabrication and electrical properties of MoS2 nanodisc-based back-gated field effect transistors.

Two-dimensional (2D) molybdenum disulfide (MoS2) is an attractive alternative semiconductor material for next-generation low-power nanoelectronic applications, due to its special structure and large bandgap. Here, we report the fabrication of large-area MoS2 nanodiscs and their incorporation into back-gated field effect transistors (FETs) whose electrical properties we characterize. The MoS2 nanodiscs, fabricated via chemical vapor deposition (CVD), are homogeneous and continuous, and their thickness of around 5 nm is equal to a few layers of MoS2.

Investigation of electronic properties of graphene/Si field-effect transistor.

We report a high-performance graphene/Si field-effect transistor fabricated via rapid chemical vapor deposition. Oligolayered graphene with a large uniform surface acts as the local gate of the graphene transistors. The scaled transconductance, gm, of the graphene transistors exceeds 3 mS/μm, and the ratio of the current switch, Ion/Ioff, is up to 100.

Fe2(SO4)3 as a binary oxidant and dopant to thin polyaniline nanowires with high conductivity.

This article exposes a facial approach to self-assemble polyaniline (PANI) nanowires with thin diameter (approximately 10 nm) and high room-temperature conductivity (approximately 10(0) S/cm) by using Fe(2)(SO(4))(3) as a binary oxidant and dopant. The new method not only saves hard templates and postprocess of template removal but also simplifies the reagent. Formation yield, diameter, and room-temperature conductivity of the nanowires are affected by the molar ratios of Fe(2)(SO(4))(3) to aniline.

Magnetic properties of conducting polymer nanostructures.

Magnetic susceptibility measurements on conducting polyaniline and polypyrrole nanostructures with different dopant type and doping level as functions of temperature and magnetic field are reported. The susceptibility data cannot be simply described as Curie-like susceptibility at lower temperatures and temperature-independent Pauli-like susceptibility at higher temperatures; some unusual transitions are observed in the temperature dependence of susceptibility, for example, paramagnetic susceptibility decreases gradually with lowering temperature, which suggests the coexistence of polarons and spinless bipolarons and possible formation of bipolarons with changing temperature or doping level. In particular, it is found that the direct current magnetic susceptibilities are strongly dependent on applied magnetic field, dopant type, and doping level.

Synthesis, property and field-emission behaviour of amorphous polypyrrole nanowires.

Polypyrrole nanowires have been electrosynthesized by direct oxidation of 0.1 mol l(-1) pyrrole in a medium of 75% isopropyl alcohol + 20% boron trifluoride diethyl etherate + 5% poly (ethylene glycol) (by volume) using porous alumina membranes as the templates. The as-prepared nanowires had a smooth surface and uniform diameter and were arranged in an orderly manner in a high density.

Electromagnetic functionalized and core-shell micro/nanostructured polypyrrole composites.

Core-shell micro/nanostructured and electromagnetic functionalized polypyrrole (PPy) composites were prepared by a self-assembly process associated with the template method in the presence of p-toluenesulfonate acid (p-TSA) as the dopant, in which the spherical hydroxyl iron (Fe[OH], 0.5-5 microm in diameter) functioned not only as the hard template, but also as the "core" of the micro/nanostructure, and the self-assembled PPy-p-TSA nanofibers (20-30 nm in diameter) acted as the "shell" (50-100 nm in thickness) of the microspheres. We found that the core-shell micro/nanostructures exhibit controllable electromagnetic properties by adjusting the mass ratio of Fe[OH] to pyrrole monomer.