Large Scale Monodisperse Hexagonal Arrays of Superparamagnetic Iron Oxides Nanodots: A Facile Block Copolymer Inclusion Method

Abstract

Highly dense hexagonal ordered arrays of superparamagnetic iron oxides nanodots are fabricated by a simple and cost-effective route. Spectroscopic, microscopic and magnetic measurements show that the nanodots have uniform size, shape and their placement mimics the original self-assembled block copolymer pattern. The nanodots show good thermal stability and strong adherence to the substrate surface, making them useful for practical device applications.

Formation of sub-7 nm feature size PS-b-P4VP block copolymer structures by solvent vapour process

“…These iron oxide nanowires arrays will be used as a hard mask for pattern transfer onto the substrate. Unlike, as mentioned in Ghoshal et al 32,33 , surface reconstruction of the block copolymer film was not performed.…”

Containing the catalyst: diameter controlled Ge nanowire growth

“…Recently, we demonstrated a facile generic method for fabricating high density arrays of hexagonally ordered inorganic nanodots on Si substrates over large areas using polystyrene-b-poly(ethylene oxide) (PS-b-PEO) BCP thin lms as a structural template. 18,19 This method is particularly useful as the feature sizes of the dots can be tuned by changing the concentration and the molecular weight of the BCP. The Ag nanodots that were formed in this process (13.7 AE 1.5 nm, Fig.…”

“…For the rst time, this article reports a combined metal assisted etching (MAE) top-down approach, 17 utilizing selfassembled arrays of nanoparticles formed using block copolymer (BCP) templates, 18,19 with bottom-up SCF growth methods, [20][21][22] to synthesise sub-20 nm Ge nanowires with narrow diameter distributions. The novel approach described in this article of "sinking" the seed particles into the substrate by MAE prior to nanowire growth, allows total inclusion of the catalytic seeds over large areas (2 cm 2 ), resulting in a high yield of nanowires.…”

Fabrication of Arrays of Lead Zirconate Titanate (PZT) Nanodots via Block Copolymer Self-Assembly

“…The formation of PZT nanodots using PS-b-PEO can be explained by the selective intra-molecular or intermolecular coordination between the metal ions (Pb 2+ , Zr 4+ , and Ti 4+ ) present in the precursor solution and the hydrophilic PEO chains present in the PS-b-PEO template. PEO is known to have a good affinity with the cationic species, 27,33 and the tendency towards multiple co-ordination is favored by its all-trans zigzag, or cishelical, configuration (Figure 3). 33 It has previously been shown that hydrogen bonding between the additives and PEO chains in a BCP can enhance the selective dispersion and interaction of the additives in the PEO matrix.…”

“…Similar interactions have been reported in the fabrication of arrays of iron oxide nanoparticles using polystyrene-block-polyethylene oxide (PS-b-PEO) thin films. 27 This metal ion impregnation method has great potential for generating ferroelectric nanostructures in a single step, without the requirement for polymer etching, as the annealing process not only crystallizes the nanostructures but also removes the polymer. This article reports the synthesis of highly ordered 2D arrays of PZT (PbZr0.3Ti0.7O3) [PZT 30/70] nanodots using selfassembled PS-b-PEO thin films.…”