Direct synthesis and characterizations of fct-structured FePt nanoparticles using poly(N-vinyl-2-pyrrolidone) as a protecting agent

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

“…Ab initio calculations involving the thermodynamic stability parameters of the fcc and fct phases have shown that the fct phase is more stable thermodynamically than the fcc phase [30]. This is consistent with other data in the literature suggesting that total or partial fct phase formation in spherical nanoparticle systems seems to be related to slow kinetic reaction conditions or high reflux temperatures [26][27][28][29]. For example, direct formation of spherical FePt nanoparticles with the fct structure [26] was observed under appropriate kinetic conditions using a slow heating rate, low temperature and gentle stirring.…”

“…The heating rate, final temperature and time used in our synthesis procedure are directly reflected in the reaction kinetics, allowing the energetically favorable arrangement of the atoms in the crystal structure, corresponding to the tetragonal phase, to be realized. The formation of a pure fct phase of PtFe has not yet been reported in the literature, and previous reports of the partial formation of the tetragonal phase have usually involved poor control over the nanoparticle morphology, resulting in polydisperse systems with large size and shape distributions [26][27][28][29]. In contrast in our work, by using a temperature-modulated process we have obtained partial L10-FePt nanorod formation with good control of size and morphology, resulting in a monodisperse system.…”

“…Furthermore, the magnetic alignment of these self-assembled L1 0 -FePt nanoparticles also has been a constant limiting factor, since the axes of easy magnetization of spherical nanoparticles are randomly oriented in three directions [25]. With the aim of avoiding these restrictions arising from magnetic alignment and A1 phase formation, a few studies in the literature have reported the synthesis of FePt nanoparticles directly in the tetragonal phase [26][27][28][29]. These studies suggested that careful control of the kinetics could be the key to fct phase formation during nanoparticle synthesis [30].…”

Application of Atomic Absorption for Determination of Metal Nanoparticles in Organic-Inorganic Nanocomposites

“…In the FT-IR spectrum www.intechopen.com of PVP/SBA-15 (Fig. 3b), the new band at 1666 cm -1 is corresponds to the carbonyl bond of PVP (Iwamoto et al, 2009). Moreover, the presence of peaks at around 2800-3000 cm -1 corresponds to the aliphatic C-H stretching in PVP/SBA-15 (Fig.…”

Chemical and physical characterizations of spinel ferrite nanoparticles containing Nd and B elements

“…2B as a function of refluxing-time at 275°C. Here, we focus attention on average XRD-diameter calculated from the Sherrer's equation using the full-width at half-maximum of (2 2 0), (3 1 1), (4 0 0), (5 1 1), and (4 4 0) peaks, respectively, since TEM-diameter and XRD-diameter are different in the case of FePt nanoparticles [27,28]. This graph suggests that TEM-diameter increases and XRD-diameter reaches a certain value as refluxing-time at 275°C increases.…”