Magnetic properties of Fe₃O₄ antidot arrays synthesized by AFIR: atomic layer deposition, focused ion beam and thermal reduction

Abstract

Magnetic films of magnetite (Fe3O4) with controlled defects, so-called antidot arrays, were synthesized by a new technique called AFIR. AFIR consists of the deposition of a thin film by atomic layer deposition, the generation of square and hexagonal arrays of holes using focused ion beam milling, and the subsequent thermal reduction of the antidot arrays. Magnetic characterizations were carried out by magneto-optic Kerr effect measurements, showing the enhancement of the coercivity for the antidot arrays. AFIR opens a new route to manufacture ordered antidot arrays of magnetic oxides with variable lattice parameters.

Tuning Nanohole Sizes in Ni Hexagonal Antidot Arrays: Large Perpendicular Magnetic Anisotropy for Spintronic Applications

“…The choice of antidot array systems is governed by its ability for tuning the physical properties of various host-patterned materials by varying the hole parameters in the nanoscale, as they are the nanohole size and their neighboring interdistance . Moreover, their ability to act as magnonic crystals, which are similar to photonic crystals for photons, exhibits a periodic potential for magnons, allowing one to modify the spin wave dispersion. , Thus, antidot arrays systems are promising candidates for applications in the field of spintronics as spin wave filters or spin waveguides. , In addition, the antidot arrays with the PMA easy axis are interesting from the application point of view in the superconductor as flux pinning centers. − Furthermore, many studies used magnetic materials with a perpendicular magnetic anisotropy as host films for the antidot lattices and declared their efficiency for magnetic recording and bit patterned media as compared to unpatterned films. , Therefore, if high effective PMA could be realized, Ni antidot array structures would be very promising candidates for spin transfer torque magnetic random-access memories (STT-MRAM) and perpendicular bit patterned magnetic storage media applications. ,, Moreover, the proposed Ni−antidots thin film system is unique in view of the long-standing challenge to promote PMA in spintronic devices, including materials with a weak spin–orbit coupling (SOC) . This fact is very important because of the existence of heavy-ions elements in the system increases the damping constant and strongly reduces the spin diffusion lengths, thus restricting magneto-resistance and preventing low critical currents for magnetization reversal, two initial key factors for STT-MRAM applications. ,, …”

“…11,12 Thus, antidot arrays systems are promising candidates for applications in the field of spintronics as spin wave filters or spin waveguides. 13,14 In addition, the antidot arrays with the PMA easy axis are interesting from the application point of view in the superconductor as flux pinning centers. 15−17 Furthermore, many studies used magnetic materials with a perpendicular magnetic anisotropy as host films for the antidot lattices and declared their efficiency for magnetic recording and bit patterned media as compared to unpatterned films.…”

Magnetic hyperthermia in cancer therapy, mechanisms, and recent advances: A review

“…There are different methods for the synthesis of Fe 3 O 4 nanoparticles including 145 :(1) Wet chemical methods such as coprecipitation, 146 oxidation, 147 sol−gel synthesis, 148 hydrothermal, 149 electrochemical, 150 nanoreactors, 151 sonochemical, 152 aerosol/vapor phase, 153 and supercritical fluid. 154 (2) Physical methods such as focused ion beam lithography 155 or gas-phase deposition.(3) Microbial methods. 145 …”

A Study of Magnetic Properties in a 2D Ferromagnetic Nanolattice through Computer Simulation

“…Antidote lattices prevent the movement of magnetic domain walls. This process changes the coercive force [ 23 , 24 , 25 , 26 ]. The pores of the lattice also affect the magnetic resistance, magnetic susceptibility, and magnetic anisotropy of the film [ 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”