Morphology and optical properties of ZnFe2O4 thin films grown by RF-magnetron sputtering

Abstract

Nanocomposite materials based on ferrites have recently become effective heterogeneous catalysts and are widely used in the purification of water systems from organic pollutants [1]. Zinc ferrite occupies a special place as a prospective semiconductor photocatalytic material due to the photoresponse in the visible light spectrum, the band gap is 1,9 eV [2]. Zinc ferrite-based film structures are insufficiently represented, although they have a technological perspective. Thus, the creation of photocatalytic systems based on zinc ferrite is an actual task. In the presented work we obtained ZnFe2O4/glass film structures using the RF-magnetron sputtering method. The target was made by pressing of zinc ferrite nanoparticles synthesized by us using the solvothermal method. The morphology of ZnFe2O4 nanoparticles and thin films was characterized by Scanning Electron Microscopy (SEM-Philips XL30 SFEG and TESCAN VEGA 5124). Optical characteristics of the obtained ZnFe2O4/glass films were measured on the Spectrophotometer UV-VIS T-80. The morphology and sizes of ZnFe2O4 nanoparticles are shown in Fig.1(a). Nanoparticles have a spherical form with dimensions from 5 to 10 nm. Because of nanoparticles high surface energy, they undergo rapid interparticle interaction and enlarge into spheres with a diameter from 80 to 120 nm. Film structures of ZnFe2O4 are flexible chain formations consisting of spherical nanoparticles with dimensions from 150 to 250 nm. In Fig.2 the data of spectrophotometric studies for ZnFe2O4/glass samples with a band gap of 1,76 eV and 2,13 eV are presented.