TY  - JOUR
A1  - Granath, Tim
A1  - Löbmann, Peer
A1  - Mandel, Karl
T1  - Oxidative Precipitation as a Versatile Method to Obtain Ferromagnetic Fe\(_{3}\)O\(_{4}\) Nano‐ and Mesocrystals Adjustable in Morphology and Magnetic Properties
T2  - Particle & Particle Systems Characterization
N2  - Oxidative precipitation is a facile synthesis method to obtain ferromagnetic iron oxide nanoparticles from ferrous salts—with unexplored potential. The concentration of base and oxidant alone strongly affects the particle's structure and thus their magnetic properties despite the same material, magnetite (Fe\(_{3}\)O\(_{4}\)), is obtained when precipitated with potassium hydroxide (KOH) from ferrous sulfate (FeSO\(_{4}\)) and treated with potassium nitrate (KNO\(_{3}\)) at appropriate temperature. Depending on the potassium hydroxide and potassium nitrate concentrations, it is possible to obtain a series of different types of either single crystals or mesocrystals. The time‐dependent mesocrystal evolution can be revealed via electron microscopy and provides insights into the process of oriented attachment, yielding faceted particles, showing a facet‐dependent reactivity. It is found that it is the nitrate and hydroxide concentration that influences the ligand exchange process and thus the crystallization pathways. The presence of sulfate ions contributes to the mesocrystal evolution as well, as sulfate apparently hinders further crystal fusion, as revealed via infrared spectroscopy. Finally, it is found that nitrite, as one possible and ecologically highly relevant reduction product occurring in nature in context with iron, only evolves if the reaction is quantitative.
KW  - colloidal nanostructures
KW  - nanoparticle aggregation
KW  - non‐classical crystallization
KW  - oriented attachment
Y1  - 2021
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/22441
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-224419
VL  - 38
IS  - 3
ER  -