Lateral displacement induced disorder in L10-FePt nanostructures by ion-implantation

Abstract

Ion implantation is a promising technique for fabricating high density bit patterned media (BPM) as it may eliminate the requirement of disk planarization. However, there has not been any notable study on the impact of implantation on BPM fabrication of FePt, particularly at nano-scale, where the lateral straggle of implanted ions may become comparable to the feature size. In this work, implantation of antimony ions in patterned and unpatterned L10-FePt thin films has been investigated. Unpatterned films implanted with high fluence of antimony exhibited reduced out-of-plane coercivity and change of magnetic anisotropy from perpendicular direction to film-plane. Interestingly, for samples implanted through patterned masks, the perpendicular anisotropy in the unimplanted region was also lost. This noteworthy observation can be attributed to the displacement of Fe and Pt atoms from the implantation sites to the unimplanted areas, thereby causing a phase disorder transformation from L10 to A1 FePt.

Synthesis of Ag ion-implanted TiO2 thin films for antibacterial application and photocatalytic performance

“…Ion-implantation induced defects can be removed by subsequent annealing process. Because of several advantages of thin films modification, such as non-contamination, easy control of the thickness and composition of ion rich layer, ion implantation was chosen in the modification of TiO 2 [38][39][40][41][42][43][44][45][46][47][48][49][50]. As to Ag ion-implantation, several studies have reported that very small (about 2-3 nm) Ag NPs were formed near the surface of TiO 2 films [44,45].…”

Probing the Role of an Atomically Thin SiNx Interlayer on the Structure of Ultrathin Carbon Films

“…Ultrathin diamond-like carbon (DLC) films are widely used in the hard disk drives (HDDs) industry to protect the surface of hard disk media and head from corrosion and mechanical wear 1 2 3 4 . With the continuously increasing demands of inexpensive and small HDDs 5 , the areal density of these drives is increasing at a rate of 20–30% annually 6 . The reduction of magnetic spacing, which is the vertical distance between the magnetic layer in media and magnetic elements in the head, is one of the most important parameters to achieve high areal density as Wallace 7 had proposed that the readback signal increases exponentially with decreasing magnetic spacing.…”

Structural Dependent Ferromagnetic-Nonmagnetic Phase Change in FePtRu Films

“…Finally, we propose a nanopatterning method for this material system. According to our previous results, the ordered 1 0 structures of FePtX were easily transformed to the disordered 1 structure under ion irradiation [15][16][17][18][19][20][21]. Figure 5 shows the schematics of a nanopatterning method using an FM-PM phase change due to the 1 0 -1 structural transformation caused by ion irradiation.…”

“…[12][13][14], which leads to excellent thermal stability of magnetization in nanometer-size structures. After ion irradiation, the ordered 1 0 FePt films undergo transformation from the hard-FM phase (high ) to the soft-FM phase (low ) with the disordered 1 structure (fcc, = = ) [15][16][17][18][19][20]. Although the 1 0 FePt is suitable for BPM, modifying its properties using ion irradiation is difficult due to the insensitivity of magnetization with ion irradiation.…”