Zirconium nitride/aluminum nitride multilayered thin films have been synthesized with a reactive sputtering technique. The electrical transport and optical properties of these multilayers have been examined by resistivity, Hall effect, and near-normal incidence reflectance and transmittance measurements. The existence of a metal-to-insulator transition and strong increase of Hall coefficient at small wavelength of composition modulation is shown. The optical response of the multilayers is systematically modified from the behavior of ...
We have measured the thermal conductivity kappa and specific heat c of synthetic diamond single crystals with carbon 13 compositions of 1.1% and 0. 07%, respectively. The specific heat of these samples has been measured in the range of 220-740 K, and we observe less than 1% difference over the entire temperature range. From a fit to the data we find that the number of oscillators per unit mass and ...
We have measured the thermal conductivity of single crystals of La(1- x)Sr(x)CuO4 from room temperature to below 1 K. While in the undoped, semiconducting material, magnetic effects play an important role at high temperature, superconducting samples are dominated by transition temperature anomalies which are consistent with electron-photon scattering as described by the BRT model. At low temperatures the thermal conductivity shows a T to the 2. 7 power dependence in ...
The longitudinal thermal conductivity along the axis of graphite fibers is reported in the temperature range 10 to 350 K. The fibers studied were prepared by graphitization of polyacrylonitrile and petroleum pitch precursors filaments, and by chemical vapor deposition. A quantitative model for the heat conduction by lattice waves is presented.
The temperature dependence of the electrical resistivity of carbon fibers has been measured at atmospheric pressure and for temperatures up to and above the melting point at 4450 Kelvin. Vapor-grown graphite fibers of different crystalline perfection were heated with electrical pulses 28 microseconds in duration. The transient reflectivity of graphite irradiated with picosecond laser pulses was also measured and the results show evidence for nonequilibrium heating. From this work, it ...
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