A novel method for controlled synthesis of nanosized hematite (a-Fe2O3) thin film on liquid–vapor interface

Abstract

Hematite (a-Fe2O3) films with a high quality surface morphology have been formed at the liquid–vapor interface using a novel approach. The surface morphology/size of the nanoparticles constituting the film is tuned in a controlled manner. It is observed that the concentration of polyvinyl alcohol in the precursor Fe3?/Fe2? solution, the concentration of ammonia (NH3) vapor, and the annealing temperature are factors influencing the surface morphology/size of nanoparticles. The diameter of the a-Fe2O3 nanoparticles inside the film is controlled to be 2–15 nm by varying the synthesis conditions, and accordingly the films have roughness in the 1.34–6.8 nm range. The prepared a-Fe2O3 films are crystalline in nature and exhibit superparamagnetic behavior at roomtemperature