Effect of the growth rate on the structural, magnetic and transport properties of NiFe thin films

In this report, a detailed study of the influence of growth rate on the structural, magnetic, and transport properties of Ni₈₁Fe₁₉ (NiFe) thin films of nominal thickness ~ 13 nm, deposited at room temperature on Si (100) substrates using DC-magnetron sputtering technique, is carried out. The growth rate is varied by altering the DC-sputtering power P_DC from 50 to 80 W while keeping all other growth parameters unchanged. All the films possess FCC structure with very low interface width (< 1 nm) as determined from the analyses of their x-ray reflectivity data. The ferromagnetic resonance (FMR) measurement is used to investigate the impact of P_DC on the effective damping parameter (\({\alpha }_{\mathrm{eff}}\)) of these NiFe thin films. The \({\alpha }_{\mathrm{eff}}\) in these films is found to be sensitive to the crystallite size, coercivity and interface width. The lowest value of \({\alpha }_{\mathrm{eff}}\) of 0.0081 ± 0.0002 was found for the sample grown at P_DC of 80 W. The temperature-dependent resistivity measurements carried out on these samples over 20–300 K temperature range revealed the dominance of electron-magnon scattering at lower temperatures (25–150 K) and electron–phonon scattering at higher temperatures (151–300 K). This study demonstrates that by appropriate tuning of the sputtering parameter, the magnetic properties of NiFe films can be directly modified as appropriate to the desired spintronic applications.