Tuning the structure and habit of iron oxide mesocrystals
2016 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, no 34, 15571-15580 p.Article in journal (Refereed) Published
A precise control over the meso-and microstructure of ordered and aligned nanoparticle assemblies, i.e., mesocrystals, is essential in the quest for exploiting the collective material properties for potential applications. In this work, we produced evaporation-induced self-assembled mesocrystals with different mesostructures and crystal habits based on iron oxide nanocubes by varying the nanocube size and shape and by applying magnetic fields. A full 3D characterization of the mesocrystals was performed using image analysis, high-resolution scanning electron microscopy and Grazing Incidence Small Angle X-ray Scattering (GISAXS). This enabled the structural determination of e.g. multi-domain mesocrystals with complex crystal habits and the quantification of interparticle distances with sub-nm precision. Mesocrystals of small nanocubes (l = 8.6-12.6 nm) are isostructural with a body centred tetragonal (bct) lattice whereas assemblies of the largest nanocubes in this study (l = 13.6 nm) additionally form a simple cubic (sc) lattice. The mesocrystal habit can be tuned from a square, hexagonal to star-like and pillar shapes depending on the particle size and shape and the strength of the applied magnetic field. Finally, we outline a qualitative phase diagram of the evaporation-induced self-assembled superparamagnetic iron oxide nanocube mesocrystals based on nanocube edge length and magnetic field strength.
Place, publisher, year, edition, pages
2016. Vol. 8, no 34, 15571-15580 p.
Nano Technology Materials Engineering
IdentifiersURN: urn:nbn:se:uu:diva-304553DOI: 10.1039/c6nr03776cISI: 000382053300017PubMedID: 27448065OAI: oai:DiVA.org:uu-304553DiVA: diva2:1033324
FunderSwedish Research CouncilEU, FP7, Seventh Framework Programme, FP7-NMP-604448Knut and Alice Wallenberg Foundation, 3DEM-NATUR