Abstract

Dependence of low temperature resistivity of iron films on thickness, substrate temperature and rate of deposition

Author(s): Santoshkumar, T.Sankarappa, P.J.Sadashivaiah

Under high vacuumconditions, using electron beamgun evaporationmethod iron films of varied thicknesses were deposited onto the glass substrates. These films have been investigated for electrical resistivity in the temperature range 80K to 300K. The residual resistance ratio, RRR, and the temperature coefficient of resistance, TCR, were determined and discussed. The power laws for the temperature dependence of resistivity have been established. The thickness dependence of electrical resistivity has been considered in terms of Fuchs-Sondheimar theory and the resistivity of infinitely thick film, ñ0, and electronmean free path, l, were determined. The influence of deposition rate of the film on resistivity has been studied. The resistivity decreased with increasing substrate temperature and that is attributed to the formation of larger crystallites with increase of substrate temperature. The deposition rate of 2 Å/s is observed to be the optimum rate at which the iron films of minimum resistivity can be produced. It is for the first time that iron films have been investigated in singlemeasuring setup for low temperature resistivity and its dependence on thickness of the film, substrate temperature and rate of deposition.