Perpendicularly self-oriented and shape-controlled L10-FePt nanorods directly synthesized by a temperature-modulated process

Abstract

The synthesis and self-assembly of tetragonal phase-containing L1 0 -Fe 55 Pt 45 nanorods with high coercive field is described. The experimental procedure resulted in a tetragonal/cubic phase ratio close to 1 : 1 for the as-synthesized nanoparticles. Using different surfactant/solvent proportions in the process allowed control of particle morphology from nanospheres to nanowires. Monodisperse nanorods with lengths of 60 ± 5 nm and diameters of 2-3 nm were self-assembled in a perpendicular oriented array onto a substrate surface using hexadecylamine as organic spacer. Magnetic alignment and properties assigned, respectively, to the shape anisotropy and the tetragonal phase suggest that the self-assembled materials are a strong candidate to solve the problem of random magnetic alignment observed in FePt nanospheres leading to applications in ultrahigh magnetic recording (UHMR) systems capable of achieving a performance of the order of terabits/in 2 .

Size and shape-controlled nanomaterials based on modified polyol and thermal decomposition approaches. A brief review.

“…FePt nanoparticles have attracted much attention from the scientific community due to its applications in biomedicine (Souza et al 2017), catalysis (Guo et al 2013) and magnetic recording (da Silva and Varanda 2011). Either face-centered cubic (fcc) and face-centered tetragonal (fct) phases of the FePt nanoparticles are crucial for these applications (Varanda and Jafelicci 2006).…”

“…The shape-controlled synthesis of FePt has also been reported for improvement of textural and magnetic alignment for magnetic media application. Nanocubes (Chen et al 2006), nanorods and nanowires (Wang et al 2007, da Silva andVaranda 2011) have been synthesized due to their anisotropic structures. Wang and coworkers reported the synthesis of fcc-FePt nanorods and nanowires by using the solvent octadecene, oleylamine as both surfactant and a reducing agent, and iron(0) pentacarbonyl as the iron source.…”

“…As extensively mentioned in the works on nanotechnology, interest from both a scientific and a technological point of view comes, respectively, from both to know and explore new and different properties inherent to the nanoscale. These unique properties of nanometer-scale materials have been investigated with its potential innovative applications, for example in energy conversion (Bott-Neto et al 2017, Gomez-Marin et al 2016, Yin et al 2014, Huang et al 2015, Lima et al 2012, environmental remediation and agriculture systems (Dasgupta et al 2015, Sozer andKokini 2009), data storage (da Silva and Varanda 2011, Marques et al 2001, 2002a, b, c, 2004 and biomedicine (Bini et al 2016, Feng and Liu 2011, Lim and Majetich 2013, Tartaj et al 2003, Beck et al 2011a. Effects of quantum confinement and the local energy disorder of surface atoms make the properties of nanoparticles strongly size-dependent (Kovalenko et al 2015, Rogach et al 2002.…”

Lithographic patterning of ferromagnetic FePt nanoparticles from a single-source bimetallic precursor containing hemiphasmidic structure for magnetic data recording media

“…Since Sun et al [15] firstly reported the synthetic method of FePt NPs by combining high temperature pyrolysis of Fe(CO) 5 with chemical reduction of Pt(acac) 2 , organic phase syntheses have been widely used to prepare FePt, FePd and CoPt NPs, owing to the distinct advantages over conventional physical methods [16,17]. Alternative counterparts of the unstable iron source were also sought, such as Fe(acac) 3 and FeCl 3 , etc [14,18]. To better control the ratio of Fe and Pt ions in NPs, single-source precursors containing iron and platinum atoms in a single molecule were designed and synthesized [19][20][21].…”

EXAFS investigation of the role of Cu on the chemical order and lattice distortion in L10Fe–Pt–Cu thin films

“…Many studies have been carried out to find the optimum conditions for the preparation of L1 0 -ordered Fe-Pt alloys in the form of nanoparticles (Sun et al, 2000;Sun, 2006;Capobianchi et al, 2009;, nanorods (da Silva & Varanda, 2011;Poudyal et al, 2009), thin films (Casoli et al, 2005), patterned systems (Goll & Bublat, 2013;Kikitsu et al, 2013) or capped magnetic structures (Makarov et al, 2008;. The systems are commonly obtained by post-deposition high-temperature treatments for a few hours in order to favour the conversion from the chemically disordered and magnetically soft face-centred cubic (A1) phase into the chemically ordered and hard facecentred tetragonal (f.c.t., L1 0 ) phase.…”