Single crystal iron nanocube synthesis via the surface energy driven growth method

Abstract

Single crystal iron nanocubes are produced by simply heating a bilayer film. This surface energy driven growth (SEDG) method exploits the difference in surface energies of the components (γ(Fe) ~ 2.2 J m(-2) versus γ(Nd) ~ 0.7 J m(-2)) in the binary alloy Fe-Nd system to produce nanocubes of the higher energy Fe component. The dimensions of the cubes range from tens to hundreds of nanometers in size and can be controlled by changing the initial thickness of iron in the deposited Fe-Nd bilayer prior to annealing at 700 °C. The composition and structure of the nanocubes was confirmed by transmission electron microscopy analysis as single crystal bcc iron in the α-phase. The cubes were found to exist as core-shell structures with the α-phase encased by an intermetallic Fe-Nd phase, characteristic of the SEDG growth mechanism.

Position Controlled Growth of Single Crystal Cu3Si Nanostructures

“…However, the lateral growth of these nanostructures, which is evident from Fig 2, reflects the availability of SiO2 surrounding the initial patterned growth locations and the ability of Cu3Si to catalyze the formation of void defects that facilitate the direct reaction of Cu atoms with the silicon substrate. 2,15 The HRTEM image of the grown nanostructure in Figure 3 η″ pattern with a 0.35 nm d spacing, which is in good agreement with previously reported measurements. 24 Based on the HRTEM (Figure 3(b)) and EDX data (see see Fig.…”

“…This is an example of a surface energy driven growth (SEDG) process in which differences in the surface energies of the components within a bilayer and the growth substrate facilitates low temperature surface diffusion, nucleation and ultimately the production of high-quality single crystal materials. [12][13][14][15] Growth is followed in real time using SEM and post growth TEM demonstrates that the nanostructures are not only single crystals but are aligned with the Si substrate lattice. Using this approach arrays of Cu3Si building blocks that range in size from 200 nm to 1 µm were fabricated with pitches of 500 nm to 8 µm.…”

Magnetization nutation induced by surface effects in nanomagnets

“…a cube. Today, nanocubes (of iron or cobalt) are routinely investigated in experiments since their synthesis has become fairly well controlled [32][33][34][35][36][37]. Here we consider a nanocube of N = 729 spins located on the vertices of a simple cubic lattice (i.e.…”

Surface effects on ferromagnetic resonance in magnetic nanocubes

“…Note that for both of these sizes high-frequency peaks are much smaller than the main low-frequency peak (notice the difference in scale between the left and right panels). By way of illustration, we consider an Fe nanocube of side a = 8 nm [5,6,12,18,31,32]. This corresponds to a nanocluster of size 27 × 27 × 27 particle whose absorption spectrum is shown in Fig.…”