Magnetic needle-like iron oxide particles prepared by microwave-assisted thermal decomposition technique

•Magnetic needles of 20 µm were prepared by a two step microwave-assisted synthesis.•This method is simple, effective and uses available cheap and low-toxic chemicals.•Prepared particles possess soft ferromagnetic behavior typical for nanoparticles.•Elongated shape, size and magnetic properties predict high application potential.

Iron oxide particles were prepared by a simple organic precursor assisted thermal decomposition technique. Microwaves were used as a source of energy for both precursor synthesis and generation of heat required for thermal decomposition. Ferrous oxalate dehydrate prepared within the microwave-assisted solvothermal process possess needle-like particle morphology with the length of about 20 µm and submicrometric diameter. Magnetic iron oxide was formed by a topotactic decomposition of prepared precursor in a microwave reactor thus the final product also preserves needle-like shape and possesses soft ferrimagnetic behavior.