A Three-Dimensional Analysis of Magnetic Nanopattern Formation in FeRh Thin Films on MgO Substrates: Implications for Spintronic Devices

Abstract

Magnetic nanopatterns were successfully created in FeRh thin film deposited on MgO (100) substrates. Silica and polystyrene spherical masks, nominally 500 and 1000 nm in diameter, respectively were applied on the surface of the sample in order to locally shadow the film against the effect of 110 keV energy neon-ion irradiation with fluences of 1015 and 1016 ions/cm2. Such nanosphere-lithography technique allows for projecting the mask geometry on the magnetic structure of the FeRh film. Conversion-electron Mössbauer spectroscopy and magnetic force microscopy were used to determine the ferromagnetic ratio and the magnetic pattern in the samples, and nuclear resonance scattering of synchrotron radiation was applied to obtain the in-depth magnetic profile. From the results obtained, the possible three-dimensional (3D) structure of the created individual magnetic domains was also constructed. Overall, the great customizability of the presented nanosphere-lithography technique in FeRh thin film provides opportunities for developing cutting-edge spintronic applications.

Resonance behavior of embedded and freestanding microscale ferromagnets

“…Therefore, the selective material removal can provide another pathway for the local modification of resonant properties, in addition to the local disordering of the B2 Fe 60 Al 40 template material itself. Indeed, embedded ferromagnetic regions have recently been obtained on other template materials [43][44][45][46] . An amplification of stray field effects can be expected in dipolarly coupled objects, since the coupling is reliant entirely on the stray field alone.…”

Laser irradiation effects in FeRh thin film

“…Recently, FeRh thin films have attracted extensive attention, due to the diversity of their possible applications [1][2][3][4]. Their near room temperature metamagnetic transition from antiferromagnetic (AF) to ferromagnetic (FM) order [5][6][7][8][9][10][11] and the interoperability between FM and paramagnetic (PM) states provide an excellent base for energy-saving spintronic devices [12][13][14][15]. Moreover, the outstanding caloric parameters and non-toxic biocompatibility of FeRh give novel alternatives for developing gas-free domestic magnetic refrigerators, or new medical applications [16][17][18][19].…”

“…One of the main challenges to turn a promising material into a nanodevice is the local implementation of the desired physical parameters. Among several techniques, the most common procedures use either a mask which determines the regions of the modifiable areas [12,20,21] or use a well-focused beam that directly damage or alters the material properties in the irradiated section [22][23][24][25][26].…”

“…Several impressing works came to light lately related to the creation of magnetic nanosturctures in FeRh [12,[27][28][29]. With focused He + irradiation, the alternation of the local metamagnetic temperature of the B2 phase was demonstrated [14], by using laser ablation nanoparticles were synthetized in liquids [15], with Ne irradiation through a spherical nanomask FM nanodomains were induced in PM matrix [12] and AF/FM transition temperature was tuned by nanoindentation [30].…”

Depth-Adjustable Magnetostructural Phase Transition in Fe60V40 Thin Films

“…Phase transitions are a powerful way to generate intrinsic property modifications in alloys. − Various types of defects including atomic scale defects such as antisites can lead to significant intrinsic property modifications. ,− In some cases, subunit cell displacements − are sufficient to cause large changes in M s . Defects can be induced via external stimuli including irradiation with ions or laser pulsing, via atomic displacements, temperature driven atomic diffusion, or a combination of these effects.…”