engleski

Transport Properties of the Ta_xN thin films

We report on the low temperature transport properties of the Ta_xN thin films deposited on the SiO₂ amorphous substrate. The results were analyzed in the light of the Ta_xN thin films investigations deposited on the sapphire substrate where <i>x</i> varied from 1.2 to 0.4 spanning thus the critical concentration of the metal.insulator transition at <i>x</i> = 0.6. During the deposition on the low cost SiO₂ amorphous substrate, the substrates were held at the same temperature, 450 ^oC, at partial N₂ pressures ranging from 50 to 100 mTorr. Thus we obtain the Ta_xN thin film alloys in a narrow range of <i>x</i>: 0.72-0.83. The transport properties show considerable and non monotonous variation with <i>x</i>, which we attribute to the local minimum in the density of the electronic states at Fermi level of the rock salt intermetallic Ta₄N₅. The temperature dependences of the resistivities, which we fit to exp(<i>T</i>/<i>T</i>₀), are also discussed.

Ta_xN thin films; resistivity; thermopower

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