Postdeposition organic coating and self-assembly of gas phase prepared FePt nanoparticles on lipid reservoir films

Abstract

A method for the postdeposition organic coating of metallic nanoparticles is introduced. FePt nanoparticles from the gas phase are deposited onto Si substrates which are pre-coated with multilayers of phospholipid molecules by spin coating. If the substrate temperature is just below or above the temperature, at which the phospholipids undergo a phase transition from the liquid crystalline into an intermediate phase, the particles are enwrapped by the lipids. The particles exhibit a clear tendency to self-assemble in regular two-dimensional particle arrangements.

Prospects for nanoparticle-based permanent magnets

“…Assembly of cluster-deposited nanoparticles, for example FePt, has been achieved by depositing them onto Si substrates, which are pre-coated with multilayers of amphiphilic phospholipid molecules [33,34].…”

A Micellar Approach to Magnetic Ultrahigh‐Density Data‐Storage Media: Extending the Limits of Current Colloidal Methods

“…[10,14] However, even in these cases, the particles still need to be encapsulated with an organic-ligand shell, either after deposition from a cluster beam [12] or during synthesis, to guarantee their ordered organization. Typical interparticle spacings are thus the same as described before, resulting in dipolar coupling and, additionally, the particle-ligand interactions can deteriorate the magnetic properties.…”

Direct Synthesis of Isolated L10 FePt Nanoparticles in a Robust TiO2 Matrix via a Combined Sol–Gel/Pyrolysis Route

“…[3] Other approaches, such as rapid annealing, [7] which has shown moderate success, or non-traditional methods for annealing based on light absorption [8] or pulsed laser heating [9] have been explored recently. Post-deposition organic coating and self-assembly of gas-phase synthesized nanoparticles, [10] as well as pre-annealing at moderate temperatures, [11] aimed at decomposing the surfactant without sintering particles, have also been suggested. Mizuno et al at Sony [12] have employed linker molecules, while researchers at Fujitsu [13] used spin-coating techniques to significantly prevent particle coalescence under high-temperature annealing.…”