Structural, Optical and Magnetic Properties of Diamagnetic Cd 2+ Incorporated Cobalt Ferrite Thin Films Deposited by Spray Pyrolysis

Cadmium (Cd 2+ )-substituted cobalt ferrite thin films with configuration Co 1− x Cd x Fe 2 O 4 ( x = 0.0 to 1.0 in steps of 0.2) were grown via spray pyrolysis. The influence of Cd 2+ substitution on structural and functional properties was investigated. X-ray diffraction analysis clearly shows a single-phase cubic spinel geometry ( Fd3m space group). The ultrafine nanocrystallites with average crystallite dimensions of 11–15 nm were obtained. The surface topography was inspected by scanning electron microscopy. The uniform distribution of the crystallites in nanosize dimensions (10–14 nm) was also supported by transmission electron microscopy. The contact angle measurements of the fabricated thin films demonstrate special affinity towards water molecules. FTIR spectra affirmed the construction of spinel ferrite structure and the band position was influenced by Cd 2+ -substitution. The optical band gap energy ( E g ) can be tuned by Cd 2+ -substitution and decreases from 2.98 to 2.10 eV viewing the semiconducting performance. The PL investigation showed the distinguishing near-band-edge emission at about 700 nm, which can be ascribed to the re-grouping of electrons with light-produced holes in oxygen vacancies and creation of intrinsic defects. Magnetic properties, i.e. saturation magnetization ( M s , 412.84–111.47 emu/cc), remanence magnetization ( M r , 44.83–2.18 emu/cc) and coercivity ( H c , 402.12–78.12 Oe), decreased with increasing diamagnetic Cd 2+ substitution due to a decrease in net magnetization.