Glycine assisted hydrothermal synthesis of α-Fe2O3 nanoparticles and its size dependent properties

α-Fe2O3 with different sizes and morphologies have been successfully synthesized via a biomolecule assisted hydrothermal method. The samples are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, UV–visible diffuse reflectance spectroscopy and vibrating sample magnetometer. A clear blue shift is observed in the optical absorption spectra, indicating that band gap increases with size reduction. Magnetic measurements reveal that coercivity and Morin transition temperature decreases as the size decreases.