Dependence of the Magnetization Process on the Thickness of Fe70Pd30 Nanostructured Thin Film

Abstract

Fe–Pd magnetic shape-memory alloys are of major importance for microsystem applications due to their magnetically driven large reversible strains under moderate stresses. In this context, we focus on the synthesis of nanostructured Fe70Pd30 shape-memory alloy antidot array thin films with different layer thicknesses in the range from 20 nm to 80 nm, deposited onto nanostructured alumina membranes. A significant change in the magnetization process of nanostructured samples was detected by varying the layer thickness. The in-plane coercivity for the antidot array samples increased with decreasing layer thickness, whereas for non-patterned films the coercive field decreased. Anomalous coercivity dependence with temperature was detected for thinner antidot array samples, observing a critical temperature at which the in-plane coercivity behavior changed. A significant reduction in the Curie temperature for antidot samples with thinner layer thicknesses was observed. We attribute these effects to complex magnetization reversal processes and the three-dimensional magnetization profile induced by the nanoholes. These findings could be of major interest in the development of novel magnetic sensors and thermo-magnetic recording patterned media based on template-assisted deposition techniques.

Dependence of Structural, Morphological and Magnetic Properties of Manganese Ferrite on Ni-Mn Substitution

“…Nanoscale materials have remarkable optical, magnetic, electrical, and catalytic properties [ 1 , 2 , 3 , 4 , 5 , 6 ]. The structure and composition of spinel nano-ferrites control the functional properties of magnetic nanosized materials [ 4 , 5 ].…”

“…In such single-domain systems, the magnetic anisotropy determines the spin alignment along the easy axis of magnetization, while the thermal fluctuations cause these spins to undergo Brownian motion along their axes [ 12 , 13 , 14 ]. As the magnetic field allows the control of the shape-memory effect, new types of microstructures may be produced by applying an external magnetic field [ 6 ]. The coercivity ( H C ), remanent magnetization ( M R ), saturation magnetization ( M S ), and anisotropy constant ( K ) are the main magnetic properties that determine the spinel ferrites applications [ 14 ].…”

Structural, Wetting and Magnetic Properties of Sputtered Fe70Pd30 Thin Film with Nanostructured Surface Induced by Dealloying Process

“…The soft magnetic behavior characterized by the single irreversible magnetization jump in the inversion process was already observed by Cialone et al [ 26 ] and by Liu et al [ 57 ] in FePd thin film with a thickness of 100 and 30 nm, respectively. Instead, the progressive increase of the magnetic field interval in which the reversal process takes places and the consequent emergence in the hysteresis loop of reversible mechanisms leading to the magnetic saturation as a function of film thickness were previously observed by Salaheldeen et al in FePd thin film on a glass substrate with thickness in the range 20–80 nm [ 58 ] and by Prida et al in Fe thin film with a thickness in the range 30–100 nm [ 59 ].…”

Enhancement of Exchange Bias and Perpendicular Magnetic Anisotropy in CoO/Co Multilayer Thin Films by Tuning the Alumina Template Nanohole Size

“…As the first anodization step produces disordered pores, a second anodization step was performed (5 h duration). A chemical etching process was carried out in 6 wt% orthophosphoric acid at 40 °C for etching times, t etch , between 25 and 75 min, to obtain NAA membranes with different pore sizes that varied in the range 34 nm ≤ D p ≤ 96 nm, as reported in our previous investigation [ 31 , 43 ].…”