Fabrication of α-Fe2O3 hexagonal disc/SnO2 nanoparticle semiconductor nanoheterostructures and its properties

Semiconductor nanoheterostructures with different weight ratios were successfully fabricated by hydrothermal method. X-ray diffraction analysis indicates that the samples were composed of α-Fe2O3 and SnO2. HRTEM images confirmed the immobilization of SnO2 nanoparticles on the surface of α-Fe2O3 hexagonal discs. Optical studies reveal that the band gaps of the samples enlarge from 1.862(2) eV to 1.9931(7) eV with increase in SnO2 weight ratio. Hysteresis behavior clearly displayed a shift of loops toward field axis for nanoheterostructures. From the ZFC curve an increase of Morin transition from 230 K to 240 K was noticed when the SnO2 weight ratio increases.