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A modified 3-omega method applied to a suspended platinum microwire was employed to measure the thermal conductivity and convective heat transfer coefficient of a water-based single-walled carbon nanotube (CNT) solution (metallic single-wall nanotubes with 1.33 nm diameter and 1.14 wt% concentration), and an expression for calculating the convective heat transfer coefficient in such a free convective fluid was introduced. The measurement technique was validated for three model systems including vacuum, air and deionized water. It is found that there is excellent agreement between these three model systems with theoretical predictions. In addition, the frequency dependence on the third harmonic response measured in deionized water reveals the existence of a very low working frequency below 60 mHz. The thermal conductivity and convective heat transfer coefficient of the nanofluid (water-based single-wall CNT solution) were determined to be 0.73 +/- 0.013 W m(-1) K(-1) and 14 900 +/- 260 W m(-2) K(-1), respectively, which correspond to an enhancement of 19.4% in thermal conductivity and 18.9% in convective heat transfer as compared to water.

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High dielectric constant aluminum oxide (Al(2)O(3)) is frequently used as the gate oxide in high electron mobility transistors and the impact of its deposition by radio frequency (RF) magnetron sputtering on the structural and electrical properties of multilayer epitaxial graphene (MLG) grown by graphitization of silicon carbide (SiC) is reported. Micro-Raman spectroscopy and temperature dependent Hall mobility measurements reveal that the processing induced changes to the structural and electrical properties of the MLG can be minimal when the oxide deposition conditions are optimal. High-resolution transmission electron microscopy (HRTEM) analysis confirms that the Al(2)O(3)/MLG interface is relatively sharp and that our thickness approximation of the MLG using angle resolved x-ray photoelectron spectroscopy (ARXPS) is accurate. An interface trap density of 5.1 × 10(10) eV(-1) cm(-2) was determined using capacitance-voltage techniques. The totality of our results indicates that ARXPS can be used as a nondestructive tool to measure the thickness of MLG, and that RF sputtered Al(2)O(3) can be used as a high dielectric (high-k) constant gate oxide in multilayer graphene based transistor applications.