Impact of Cd2+ substituted ZnAl2O4 spinel nanoparticles on structural, optical, morphological, magnetic and nonlinear optical behaviour

Abstract

Cadmium-substituted ZnAl2O4 (CdxZn(1-x)Al2O4, where x = 0, 0.1, 0.3, and 0.5) nanoparticles were synthesized by the microwave combustion process. The XRD analysis confirmed the cubic system. The crystallite size of Cd2+ doped ZnAl2O4isin the range between 20.82 and 15.12 nm. Fourier transform infrared (FT-IR) spectra are displayed the stretching frequencies. The energy gap values decrease from 4.15 to 2.67 eV with increasing doping concentrations of Cd2+, which is due to the formation of sub-bands and is calculated by the Kubelka-Munk function. HR-SEM pictures showed the features of nanoclusters grain boundaries. The elemental mixing of Zn2+/Cd2+, Al3+andO2− was confirmed by EDX analysis. Magnetic properties reveal that the undoped ZnAl2O4 has diamagnetism and Cd2+ doped ZnAl2O4 system has superparamagnetic behaviour. The nonlinear index of refraction (10−8 cm2/W), nonlinear absorption coefficient (10−4 cm/W) and the 3rd order nonlinear susceptibility (10−6 esu) are found out by Z-scan experiments. The obtained results of optical limiting analysis confirm that these materials are viable candidates for devices like optical power limiters and optical switches.