Temperature-Dependent Magnetoresistance in Polycrystalline Ni81Fe19 Thin Film on Si (100)

Magnetoresistance (MR) in thin films stems from different types of scattering mechanism present in the film. We report a systematic study of the temperature-dependent magnetoresistance behaviour in the pulsed DC magnetron sputtered Ni81Fe19 thin film on Si (100). X-ray diffraction study reveals the polycrystalline nature of the film along with the presence of preferred orientation. X-ray reflectivity measurement shows very low interface roughness (0.55 +/- 0.04 nm). Temperature-dependent resistivity measurement is performed over a temperature range of 25-300 K, unveiling the dominance of electron-magnon scattering and impurity scattering at lower temperature (25-250 K) and electron-phonon scattering at higher temperature (above 250 K). In the investigated temperature range (30-300 K), the MR magnitude is found to reduce from 0.97 to 0.51% with increment in measurement temperature from 30 to 300 K. This reduction is attributed to the enhancement in phonon scattering at higher temperatures, and relatively suppressed ordering influence of magnetic field at higher temperature due to higher thermal activation energy and impurity scattering.