One-step fabrication of L1 FePt nanocubes and rods by cluster beam deposition

Abstract

, "One-step fabrication of L10 FePt nanocubes and rods by cluster beam deposition" (2012 In this work, single crystal L1 0 FePt nanocubes have been successfully produced by a cluster beam deposition technique without the need of post annealing. Particles have been deposited by dc magnetron sputtering using high Ar pressures on both single crystal Si substrates and Au grids for the measurement of magnetic and structural properties, respectively. The nanocubes have a uniform size distribution with an average size of 5 nm. At 1 Torr, the particles have the L1 0 structure with an order parameter of 0.5 and a RT coercivity of 2 kOe with high switching fields observed in the hysteresis loop. Further annealing increased the particle size to 20 nm and the RT coercivity to 10.2 kOe with perfect chemical ordering. In addition to these nanocubes, micron size rods with the L1 0 structure have been observed near the cluster gun. SEM analysis showed that these rods consist of nanoparticles with 20 nm average size. Surfactant assisted high-energy ball milling has been used to separate the nanoparticles from the rods. After one hour of milling, these 20 nm particles showed a room temperature coercivity of 9 kOe with an order parameter of 0.85. These FePt nanocubes have a potential for use in the development of future high-density magnetic recording media because of their high coercivity, good shape and very narrow size distribution.

Well protected SmCo nanoclusters: fabrication and transformation to single crystals

“…13 It has also been used for synthesis of rare earth, [9][10][11][12] and rare-earth-free magnetic nanoparticles. [14][15][16] Generally, nanostructures were synthesized with CBD technique by optimizing sputtering power, inert gas ow and aggregation length. Sputtering power is driving force in CBD system to obtain desired crystalline structure.…”

Low pressure bottom-up synthesis of metal@oxide and oxide nanoparticles: control of structure and functional properties

“…In some experiments, after having grown the NPs with LPGAS, thermal annealing was performed in-flight, by allowing the NP beam to flow through an oven [96]. In other works, a careful optimization of the design of the magnetron, the sputtering target, and of the parameters governing the sputtering and the NP condensation (sputtering voltage, current density, and inert gas pressure) permitted the direct synthesis of monodispersed FePt NP in the L1 0 phase [93,97,98] (see figure 17).…”

Size-dependent magnetic properties in Nd–(Fe, Mn)–B nanoparticles

“…This phenomenon is significant not only to our understanding of nature, but also to our current technology as efforts continue to create smaller and smaller devices. Previous studies revealed novel behavior in the optical and magnetic properties as the size of the system is decreased (Andres et al 1989;Schneider et al 1990;Gavrin et al 1990; Akdogan et al 2012Akdogan et al , 2013. Of fundamental importance is the behavior of the Curie temperature in ferromagnetic systems.…”