Relation of thickness and some physical properties of NiFe thin films

Abstract

The magnetic properties of rf sputtered Ni81Fe19 films were studied as a function of thickness from <100 to ∼1200 Å. In contrast to some recently reported studies, there was no evidence of an oscillatory dependence of resistivity on Δρ as a function of thickness. The magnetoresistance, resistance, coercivity, and anisotropy field varied smoothly with thickness. In contrast, the magnetostriction λs had a minimum of −1.5×10−6 at ∼300 Å. The saturation magnetic moment did not decrease with thickness over the thickness range studied here. The derived magnetoresistance of an ‘‘infinitely’’ thick film was 3.92% compared to the bulk value of ∼4%. The analysis indicates that surface and grain-boundary scattering are the primary cause of lower than bulk values of magnetoresistance in these thin permalloy films.

High‐Quality NiFe Thin Films on Oxide/Non‐Oxide Platforms via Pulsed Laser Deposition at Room Temperature

“…The decrease of M s with decreasing film thickness is in qualitative agreement with several previous reports on thickness dependence of saturation magnetization in Ni 1−x Fe x thin films. [22][23][24][25] The magnetic dead layer, which can be deduced by extrapolating M s -t relation to M s → 0, is ≈2 and ≈3 nm for F L = 3 and 4 J cm −2 , respectively. In addition, to demonstrate the variation in M s across different substrates, substrate-dependent M s of 20 nm thin NiFe films is also observed, as shown in Figure 2d.…”

Artificial multiferroic structures using soft magnetostrictive bilayers on Pb(Mg1/3Nb2/3)–PbTiO3

“…MOKE magnetometry measures the top ~20nm of thin magnetic films, due to the laser attenuation within the film. This penetration distance is known as the skin depth and is dependent on the laser frequency (4.7x10 14 Hz) and the film resistivity, which for thin NiFe films is known to change as a function of thickness [16]. From previous work [14], a double step was observed in hysteresis loops for similar soft magnetic bilayer films with 25nm top layer thickness, due to the two magnetic layers not being exchanged coupled.…”

Unusual magnetization characteristics of Fe-Ni films with graded composition

“…These magnetostrictive properties can be modified by the surface morphology and the microstructure of ultrathin films. [2][3][4] Consequently, Ni-Fe alloys found applications as popular soft magnetic alloys, Invar and Elinvar alloys and magnetostrictive materials. Other useful properties of Permalloys are their relatively large anisotropic magnetoresistance and induced magnetic anisotropy.…”