Low-Temperature DC Carrier Transport in (Co_(0.45)Fe_(0.45)Zr_(0.10))_x(Al_2O_3)_(1-x) Nanocomposites Sputtered in Mixed Argon-Oxygen Atmosphere

摘要

This paper studies the temperature dependences (2 ＜ T ＜ 300 K) of the DC conductivity σ(T) for the (Co_(0.45)Fe_(0.45)Zr_(0.10))_x(Al_2O_3)_(1-x) nanocomposites (30 ＜ x ＜ 65 at.%) sputtered in Ar + O_2 atmosphere. It is shown that at temperatures lower than 100-150 K dependences of DC conductance on temperature for all the studied samples are due to the Shklovski-Efros variable range hopping mechanism. It was also observed that σ(x,T) dependences can be attributed to the formation of FeCo-based oxide "shells" around metallic alloy nanoparticles due to incorporation of oxygen in the vacuum chamber during the deposition procedure.