Researchers at Saint Petersburg University have synthesized microhelices of iron compounds with a diameter of approximately 12 μm, which can be used to manufacture inductors

Chemists at Saint Petersburg University in Russia have successfully synthesized microhelices of iron compounds with a diameter of approximately 12 μm—about one-tenth the thickness of a human hair. These microhelices can be used to manufacture highly sensitive sensors, catalysts, as well as miniature electromagnets or inductors.

To achieve such microscopic structures, the chemists developed a simple and effective synthesis method that utilizes interfacial interactions to obtain iron-based compound microhelices.

Due to the interaction between the aqueous iron salt solution and gaseous ammonia, a Fe(OH)₃ film is formed. After drying, it transforms into Fe(OH)₃ microhelices with diameters up to 10 μm. These microhelices can be converted into Fe₂O₃ microhelices by annealing in air. Further hydrogen reduction produces Fe microhelices.