A Controllability Investigation of Magnetic Properties for FePt Alloy Nanocomposite Thin Films

Abstract

An appropriate writing field is very important for magnetic storage application of L10 FePt nanocomposite thin films. However, the applications of pure L10 FePt are limited due to its large coercivity. In this paper, the ratios of L10 and non-L10 phase FePt alloy nanoparticles in FePt/MgO (100) nanocomposite thin films were successfully tuned by pulsed laser deposition method. By adjusting the pulsed laser energy density from 3 to 7 J/cm2, the ordering parameter initially increased, and then decreased. The highest ordering parameter of 0.9 was obtained at the pulsed laser energy density of 5 J/cm2. At this maximum value, the sample had the least amount of the soft magnetic phase of almost 0%, as analyzed by a magnetic susceptibility study. The saturation magnetization decreased with the increase in the content of soft magnetic phase. Therefore, the magnetic properties of FePt nanocomposite thin films can be controlled, which would be beneficial for the magnetic applications of these thin films.

Highly Coercive L10-Phase Dots Obtained through Low Temperature Annealing for Nano-Logic Magnetic Structures

“…In addition to the occurrence of the superlattice peaks (001) and ( 110) another distinct signature of the occurrence of the tetragonal L1 0 phase is the fact that the (200), ( 220) and (311) peaks are split into two. Such a feature has been encountered in other works on FePt [20][21][22] and has been unambiguously regarded as further proof of the occurrence of the L1 0 phase, this being due to the tetragonally distorted planes, giving rise to the spectral splitting observed in these peaks. Upon the fitting of the XRD spectra, we have also derived the average crystallite size of the L1 0 FePt.…”

“…In addition to the occurrence of the superlattice peaks (001) and ( 110) another distinct signature of the occurrence of the tetragonal L10 phase is the fact that the (200), ( 220) and (311) peaks are split into two. Such a feature has been encountered in other works on FePt [20][21][22] and has been unambiguously regarded There is a strong presence of the superlattice peaks: (001) and (110) diffraction lines, as well as the presence of the main (111) Bragg lines followed by other superlattice peaks: distinctly split (200) fundamental reflection, recorded at around 48-49 degrees in 2 theta. It has to be mentioned that the two main superlattice peaks of tetragonal L1 0 , the (001) and (110) reflections, occurs for the Cu Kα radiation we used at about 23 • and 32 • , respectively.…”

Lithographically Ordered FePt L10 Dots with High Coercivity for Logic-Conditioned Magnetic Nanostructures

“…Beyond the occurrence of the superlattice peaks ( 001) and ( 110), another distinct signature of the occurrence of the tetragonal L1 0 phase is the fact that the (200), ( 220) and (311) peaks are split into two. Such a feature has been encountered in other works on FePt [20][21][22] and has been unambiguously regarded as a further proof of the occurrence of the L1 0 phase, this being due to the tetragonally distorted planes and giving rise to the spectral splitting observed in these peaks. Upon the fitting of the XRD spectra, we have also derived the average crystallographic grain size of the L1 0 FePt.…”