30 مهر 1398
ولي دلوجي

ولی دلوجی

مرتبه علمی: دانشیار
نشانی:
تحصیلات: دکترای تخصصی / فیزیک حالت جامد
تلفن: 0813339841
دانشکده: علوم پایه

مشخصات پژوهش

عنوان
Carbon films embedded by nickel nanoparticles: fluctuation in hopping rate and variable-range hopping with respect to annealing temperature
نوع پژوهش مقاله چاپ شده
کلیدواژه‌ها
Carbon films, activation energy, hopping energy
سال
2016
مجله APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
پژوهشگران ولی دلوجی

چکیده

In this work, the electrical properties of carbon– nickel films annealed at different temperatures (573, 773, 1073 and 1273 K) in the temperature range 15–300 K were investigated. The films were grown by radio frequency magnetron co-sputtering on quartz substrates at room temperature. The multiphonon hopping conduction mechanism is found to dominate the electrical transport in the temperature range 150–300 K. It can be seen that the roomtemperature hopping rate (CRT) at 773 K has maximum value of 56.8 9 105 s-1. Our results of conductivity measurements at high temperature are in good agreement with strong carrier–lattice coupling model; on the other hand, the conductivity in the range 15–50 K is well described in terms of variable-range hopping (VRH) conduction mechanism. The localized state density around Fermi level N(EF) and the average hopping energy Whop at low temperature for the films annealed at 773 K have maximum value of 2.23 9 1023 (cm-3 eV-1) and minimum value of 9.74 9 10-4 eV, respectively.